cantera/SConstruct

"""
SCons build script for Cantera

Basic usage:
    'scons help' - Show this help message.

    'scons build' - Compile Cantera and the language interfaces using
                    default options.

    'scons clean' - Delete files created while building Cantera.

    'scons install' - Install Cantera.

    'scons uninstall' - Uninstall Cantera.

    'scons test' - Run all tests which did not previously pass or for which the
                   results may have changed.

    'scons test-reset' - Reset the passing status of all tests.

    'scons test-clean' - Delete files created while running the tests.

    'scons test-help' - List available tests.

    'scons test-NAME' - Run the test named "NAME".

    'scons <command> dump' - Dump the state of the SCons environment to the
                             screen instead of doing <command>, for example
                             'scons build dump'. For debugging purposes.

    'scons samples' - Compile the C++ and Fortran samples.

    'scons msi' - Build a Windows installer (.msi) for Cantera.

    'scons sphinx' - Build the Sphinx documentation

    'scons doxygen' - Build the Doxygen documentation

Additional help command options:
    'scons help --options' - Print a description of user-specifiable options.

    'scons help --list-options' - Print formatted list of available options.

    'scons help --option=<opt>' - Print the description of a specific option
                                  with name <opt>, for example
                                  'scons help --option=prefix'
"""
# Note that 'scons help' supports additional command options that are intended for
# internal use (debugging or reST parsing of options) and thus are not listed above:
#  --defaults ... list default values for all supported platforms
#  --restructured-text ... format configuration as reST
#  --dev ... add '-dev' to reST output
#  --output=<fname> ... send output to file (reST only)

# This f-string is deliberately here to trigger a SyntaxError when
# SConstruct is parsed by Python 2. This seems to be the most robust
# and simplest option that will reliably trigger an error in Python 2
# and provide actionable feedback for users.
python_min_build_support = "3.7"
f"""
Cantera must be built using Python 3.7 or higher. You can invoke SCons by executing
    python3 `which scons`
followed by any desired options.
"""

from pathlib import Path
import sys
import os
import platform
import subprocess
import re
import textwrap
from os.path import join as pjoin
from pkg_resources import parse_version
import SCons

# ensure that Python version is sufficient for build process
python_version = "{v.major}.{v.minor}".format(v=sys.version_info)
if parse_version(python_version) < parse_version(python_min_build_support):
    print(
        f"ERROR: Cantera must be built using Python {python_min_build_support} or "
        f"higher; Python {python_version} is not supported.", file=sys.stderr)
    sys.exit(1)

from buildutils import *

if not COMMAND_LINE_TARGETS:
    # Print usage help
    logger.error("Missing command argument: type 'scons help' for information.")
    sys.exit(1)

if parse_version(SCons.__version__) < parse_version("3.0.0"):
    logger.error("Cantera requires SCons with a minimum version of 3.0.0. Exiting.")
    sys.exit(1)

if os.name not in ["nt", "posix"]:
    logger.error(f"Error: Unrecognized operating system '{os.name}'")
    sys.exit(1)

valid_commands = ("build", "clean", "install", "uninstall",
                  "help", "msi", "samples", "sphinx", "doxygen", "dump",
                  "sdist")

for command in COMMAND_LINE_TARGETS:
    if command not in valid_commands and not command.startswith('test'):
        logger.error("Unrecognized command line target: {!r}", command)
        sys.exit(1)

if "clean" in COMMAND_LINE_TARGETS:
    remove_directory("build")
    remove_directory("stage")
    remove_directory(".sconf_temp")
    remove_directory("test/work")
    remove_file(".sconsign.dblite")
    remove_file("include/cantera/base/config.h")
    remove_file("src/pch/system.h.gch")
    remove_directory("include/cantera/ext")
    remove_file("config.log")
    remove_directory("doc/sphinx/matlab/examples")
    remove_file("doc/sphinx/matlab/examples.rst")
    for name in Path("doc/sphinx/matlab/").glob("**/*.rst"):
        if name.name != "index.rst":
            remove_file(name)
    remove_directory("doc/sphinx/cython/examples")
    remove_file("doc/sphinx/cython/examples.rst")
    for name in Path(".").glob("*.msi"):
        remove_file(name)
    for name in Path("site_scons").glob("**/*.pyc"):
        remove_file(name)
    remove_file("interfaces/matlab/toolbox/cantera_shared.dll")
    remove_file("interfaces/matlab/Contents.m")
    remove_file("interfaces/matlab/ctpath.m")
    for name in Path("interfaces/matlab/toolbox").glob("ctmethods.*"):
        remove_file(name)

    print("Done removing output files.")

    if COMMAND_LINE_TARGETS == ["clean"]:
        # Just exit if there's nothing else to do
        sys.exit(0)
    else:
        Alias("clean", [])

if "test-clean" in COMMAND_LINE_TARGETS:
    remove_directory("build/test")
    remove_directory("test/work")
    remove_directory("build/python_local")

logger.info("SCons is using the following Python interpreter: {}", sys.executable)

# ******************************************
# *** Specify defaults for SCons options ***
# ******************************************

windows_options = [
    Option(
        "msvc_version",
        """Version of Visual Studio to use. The default is the newest
           installed version. Specify '12.0' for Visual Studio 2013, '14.0' for
           Visual Studio 2015, '14.1' ('14.1x') Visual Studio 2017, '14.2'
           ('14.2x') for Visual Studio 2019, or '14.3' ('14.3x') for
           Visual Studio 2022. For version numbers in parentheses,
           'x' is a placeholder for a minor version number. Windows MSVC only.""",
        ""),
    EnumOption(
        "target_arch",
        """Target architecture. The default is the same architecture as the
           installed version of Python. Windows only.""",
        {"Windows": "amd64"},
        ("amd64", "x86")),
    EnumOption(
        "toolchain",
        """The preferred compiler toolchain. If MSVC is not on the path but
           'g++' is on the path, 'mingw' is used as a backup. Windows only.""",
        {"Windows": "msvc"},
        ("msvc", "mingw", "intel")),
]

config_options = [
    Option(
        "CXX",
        "The C++ compiler to use.",
        "${CXX}"),
    Option(
        "cxx_flags",
        """Compiler flags passed to the C++ compiler only. Separate multiple
           options with spaces, for example, "cxx_flags='-g -Wextra -O3 --std=c++11'"
           """,
        {
            "cl": "/EHsc",
            "Cygwin": "-std=gnu++11", # See http://stackoverflow.com/questions/18784112
            "default": "-std=c++11"
        }),
    Option(
        "CC",
        "The C compiler to use. This is only used to compile CVODE.",
        "${CC}"),
    Option(
        "cc_flags",
        """Compiler flags passed to both the C and C++ compilers, regardless of
           optimization level.""",
        {
            "cl": "/MD /nologo /D_SCL_SECURE_NO_WARNINGS /D_CRT_SECURE_NO_WARNINGS",
            "clang": "-fcolor-diagnostics",
            "default": "",
        }),
    PathOption(
        "prefix",
        r"""Set this to the directory where Cantera should be installed. If the Python
           executable found during compilation is managed by 'conda', the installation
           'prefix' defaults to the corresponding environment and the 'conda' layout
           will be used for installation (specifying any of the options 'prefix',
           'python_prefix', 'python_cmd', or 'layout' will override this default). On
           Windows systems, '$ProgramFiles' typically refers to "C:\Program Files".""",
        {"Windows": r"$ProgramFiles\Cantera", "default": "/usr/local"},
        PathVariable.PathAccept),
    PathOption(
        "libdirname",
        """Set this to the directory where Cantera libraries should be installed.
           Some distributions (for example, Fedora/RHEL) use 'lib64' instead of 'lib'
           on 64-bit systems or could use some other library directory name instead of
           'lib', depending on architecture and profile (for example, Gentoo 'libx32'
           on x32 profile). If the user didn't set the 'libdirname' configuration
           variable, set it to the default value 'lib'""",
        "lib", PathVariable.PathAccept),
    EnumOption(
        "python_package",
        """If you plan to work in Python, then you need the 'full' Cantera Python
           package. If, on the other hand, you will only use Cantera from some
           other language (for example, MATLAB or Fortran 90/95) and only need Python
           to process YAML files, then you only need a 'minimal' subset of the
           package and Cython and NumPy are not necessary. The 'none' option
           doesn't install any components of the Python interface. The default
           behavior is to build the full Python module for whichever version of
           Python is running SCons if the required prerequisites (NumPy and
           Cython) are installed. Note: 'y' is a synonym for 'full' and 'n'
           is a synonym for 'none'.""",
        "default", ("full", "minimal", "none", "n", "y", "default")),
    BoolOption(
        "python_sdist",
        """Setting this option to True builds the Python sdist.""",
        False),
    PathOption(
        "python_cmd",
        """Cantera needs to know where to find the Python interpreter. If
           'PYTHON_CMD' is not set, then the configuration process will use the
           same Python interpreter being used by SCons.""",
        "${PYTHON_CMD}",
        PathVariable.PathAccept),
    PathOption(
        "python_prefix",
        """Use this option if you want to install the Cantera Python package to
           an alternate location. On Unix-like systems, the default is the same
           as the 'prefix' option. If the 'python_prefix' option is set to
           the empty string or the 'prefix' option is not set, then the package
           will be installed to the system default 'site-packages' directory.
           To install to the current user's 'site-packages' directory, use
           'python_prefix=USER'.""",
        {"default": ""},
        PathVariable.PathAccept),
    EnumOption(
        "matlab_toolbox",
        """This variable controls whether the MATLAB toolbox will be built. If
           set to 'y', you will also need to set the value of the 'matlab_path'
           variable. If set to 'default', the MATLAB toolbox will be built if
           'matlab_path' is set.""",
        "default", ("y", "n", "default")),
    PathOption(
        "matlab_path",
        """Path to the MATLAB install directory. This should be the directory
           containing the 'extern', 'bin', etc. subdirectories. Typical values
           are: "C:\\Program Files\\MATLAB\\R2021a" on Windows,
           "/Applications/MATLAB_R2021a.app" on macOS, or
           "/opt/MATLAB/R2021a" on Linux.""",
        "", PathVariable.PathAccept),
    EnumOption(
        "f90_interface",
        """This variable controls whether the Fortran 90/95 interface will be
           built. If set to 'default', the builder will look for a compatible
           Fortran compiler in the 'PATH' environment variable, and compile
           the Fortran 90 interface if one is found.""",
        "default", ("y", "n", "default")),
    PathOption(
        "FORTRAN",
        """The Fortran (90) compiler. If unspecified, the builder will look for a
           compatible compiler (pgfortran, gfortran, ifort, ifx, g95) in the 'PATH'
           environment variable. Used only for compiling the Fortran 90 interface.""",
        "", PathVariable.PathAccept),
    Option(
        "FORTRANFLAGS",
        "Compilation options for the Fortran (90) compiler.",
        "-O3"),
    BoolOption(
        "coverage",
        """Enable collection of code coverage information with gcov.
           Available only when compiling with gcc.""",
        False),
    BoolOption(
        "doxygen_docs",
        "Build HTML documentation for the C++ interface using Doxygen.",
        False),
    BoolOption(
        "sphinx_docs",
        "Build HTML documentation for Cantera using Sphinx.",
        False),
    PathOption(
        "sphinx_cmd",
        "Command to use for building the Sphinx documentation.",
        "sphinx-build", PathVariable.PathAccept),
    Option(
        "sphinx_options",
        """Options passed to the 'sphinx_cmd' command line. Separate multiple
           options with spaces, for example, "-W --keep-going".""",
        "-W --keep-going"),
    EnumOption(
        "system_eigen",
        """Select whether to use Eigen from a system installation ('y'), from a
           Git submodule ('n'), or to decide automatically ('default'). If Eigen
           is not installed directly into a system include directory, for example, it
           is installed in '/opt/include/eigen3/Eigen', then you will need to add
           '/opt/include/eigen3' to 'extra_inc_dirs'.
           """,
        "default", ("default", "y", "n")),
    EnumOption(
        "system_fmt",
        """Select whether to use the fmt library from a system installation
           ('y'), from a Git submodule ('n'), or to decide automatically
           ('default'). If you do not want to use the Git submodule and fmt
           is not installed directly into system include and library
           directories, then you will need to add those directories to
           'extra_inc_dirs' and 'extra_lib_dirs'. This installation of fmt
           must include the shared version of the library, for example,
           'libfmt.so'.""",
        "default", ("default", "y", "n")),
    EnumOption(
        "system_yamlcpp",
        """Select whether to use the yaml-cpp library from a system installation
           ('y'), from a Git submodule ('n'), or to decide automatically
           ('default'). If yaml-cpp is not installed directly into system
           include and library directories, then you will need to add those
           directories to 'extra_inc_dirs' and 'extra_lib_dirs'.""",
        "default", ("default", "y", "n")),
    EnumOption(
        "system_sundials",
        """Select whether to use SUNDIALS from a system installation ('y'), from
           a Git submodule ('n'), or to decide automatically ('default').
           Specifying 'sundials_include' or 'sundials_libdir' changes the
           default to 'y'.""",
        "default", ("default", "y", "n")),
    PathOption(
        "sundials_include",
        """The directory where the SUNDIALS header files are installed. This
           should be the directory that contains the "cvodes", "nvector", etc.
           subdirectories. Not needed if the headers are installed in a
           standard location, for example, '/usr/include'.""",
        "", PathVariable.PathAccept),
    PathOption(
        "sundials_libdir",
        """The directory where the SUNDIALS static libraries are installed.
           Not needed if the libraries are installed in a standard location,
           for example, '/usr/lib'.""",
        "", PathVariable.PathAccept),
    Option(
        "blas_lapack_libs",
        """Cantera can use BLAS and LAPACK libraries available on your system if
           you have optimized versions available (for example, Intel MKL). Otherwise,
           Cantera will use Eigen for linear algebra support. To use BLAS
           and LAPACK, set 'blas_lapack_libs' to the the list of libraries
           that should be passed to the linker, separated by commas, for example,
           "lapack,blas" or "lapack,f77blas,cblas,atlas". Eigen is required
           whether or not BLAS/LAPACK are used.""",
        ""),
    PathOption(
        "blas_lapack_dir",
        """Directory containing the libraries specified by 'blas_lapack_libs'. Not
           needed if the libraries are installed in a standard location, for example,
           '/usr/lib'.""",
        "", PathVariable.PathAccept),
    EnumOption(
        "lapack_names",
        """Set depending on whether the procedure names in the specified
           libraries are lowercase or uppercase. If you don't know, run 'nm' on
           the library file (for example, "nm libblas.a").""",
        "lower", ("lower", "upper")),
    BoolOption(
        "lapack_ftn_trailing_underscore",
        """Controls whether the LAPACK functions have a trailing underscore
           in the Fortran libraries.""",
        True),
    BoolOption(
        "lapack_ftn_string_len_at_end",
        """Controls whether the LAPACK functions have the string length
           argument at the end of the argument list ('yes') or after
           each argument ('no') in the Fortran libraries.""",
        True),
    EnumOption(
        "googletest",
        """Select whether to use gtest/gmock from system
           installation ('system'), from a Git submodule ('submodule'), to decide
           automatically ('default') or don't look for gtest/gmock ('none')
           and don't run tests that depend on gtest/gmock.""",
        "default", ("default", "system", "submodule", "none")),
    Option(
        "env_vars",
        """Environment variables to propagate through to SCons. Either the
           string 'all' or a comma separated list of variable names, for example,
           'LD_LIBRARY_PATH,HOME'.""",
        "PATH,LD_LIBRARY_PATH,PYTHONPATH"),
    BoolOption(
        "use_pch",
        "Use a precompiled-header to speed up compilation",
        {"icc": False, "default": True}),
    Option(
        "pch_flags",
        "Compiler flags when using precompiled-header.",
        {
            "cl": "/FIpch/system.h",
            "gcc": "-include src/pch/system.h",
            "icx": "-include-pch src/pch/system.h.gch",
            "clang": "-include-pch src/pch/system.h.gch",
            "default": "",
        }),
    Option(
        "thread_flags",
        "Compiler and linker flags for POSIX multithreading support.",
        {"Windows": "", "macOS": "", "default": "-pthread"}),
    BoolOption(
        "optimize",
        """Enable extra compiler optimizations specified by the
           'optimize_flags' variable, instead of the flags specified by the
           'no_optimize_flags' variable.""",
        True),
    Option(
        "optimize_flags",
        "Additional compiler flags passed to the C/C++ compiler when 'optimize=yes'.",
        {
            "cl": "/O2",
            "icc": "-O3 -fp-model precise",
            "icx": "-O3 -fp-model precise", # cannot assume finite math
            "gcc": "-O3 -Wno-inline",
            "default": "-O3",
        }),
    Option(
        "no_optimize_flags",
        "Additional compiler flags passed to the C/C++ compiler when 'optimize=no'.",
        {"cl": "/Od /Ob0", "default": "-O0"}),
    BoolOption(
        "debug",
        "Enable compiler debugging symbols.",
        True),
    Option(
        "debug_flags",
        "Additional compiler flags passed to the C/C++ compiler when 'debug=yes'.",
        {"cl": "/Zi /Fd${TARGET}.pdb", "default": "-g"}),
    Option(
        "no_debug_flags",
        "Additional compiler flags passed to the C/C++ compiler when 'debug=no'.",
        ""),
    Option(
        "debug_linker_flags",
        "Additional options passed to the linker when 'debug=yes'.",
        {"cl": "/DEBUG", "default": ""}),
    Option(
        "no_debug_linker_flags",
        "Additional options passed to the linker when 'debug=no'.",
        ""),
    Option(
        "warning_flags",
        """Additional compiler flags passed to the C/C++ compiler to enable
           extra warnings. Used only when compiling source code that is part
           of Cantera (for example, excluding code in the 'ext' directory).""",
        {
            "cl": "/W3",
            "default": "-Wall",
        }),
    Option(
        "extra_inc_dirs",
        """Additional directories to search for header files, with multiple
           directories separated by colons (*nix, macOS) or semicolons (Windows).
           If an active 'conda' environment is detected, the corresponding include
           path is automatically added.""",
        ""),
    Option(
        "extra_lib_dirs",
        """Additional directories to search for libraries, with multiple
           directories separated by colons (*nix, macOS) or semicolons (Windows).
           If an active 'conda' environment is detected, the corresponding library
           path is automatically added.""",
        ""),
    PathOption(
        "boost_inc_dir",
        """Location of the Boost header files. Not needed if the headers are
           installed in a standard location, for example, '/usr/include'.""",
        "",
        PathVariable.PathAccept),
    PathOption(
        "stage_dir",
        """Directory relative to the Cantera source directory to be
           used as a staging area for building for example, a Debian
           package. If specified, 'scons install' will install files
           to 'stage_dir/prefix/...'.""",
        "",
        PathVariable.PathAccept),
    BoolOption(
        "VERBOSE",
        "Create verbose output about what SCons is doing.",
        False),
    Option(
        "gtest_flags",
        """Additional options passed to each GTest test suite, for example,
           '--gtest_filter=*pattern*'. Separate multiple options with spaces.""",
        ""),
    BoolOption(
        "renamed_shared_libraries",
        """If this option is turned on, the shared libraries that are created
           will be renamed to have a '_shared' extension added to their base name.
           If not, the base names will be the same as the static libraries.
           In some cases this simplifies subsequent linking environments with
           static libraries and avoids a bug with using valgrind with
           the '-static' linking flag.""",
        True),
    BoolOption(
        "versioned_shared_library",
        """If enabled, create a versioned shared library, with symlinks to the
           more generic library name, for example, 'libcantera_shared.so.2.5.0' as the
           actual library and 'libcantera_shared.so' and 'libcantera_shared.so.2'
           as symlinks.""",
        {"mingw": False, "default": True}),
    BoolOption(
        "use_rpath_linkage",
        """If enabled, link to all shared libraries using 'rpath', i.e., a fixed
           run-time search path for dynamic library loading.""",
        True),
    Option(
        "openmp_flag",
        """Compiler flags used for multiprocessing (only used to generate sample build
           scripts).""",
        {
            "cl": "/openmp",
            "icc": "-qopenmp",
            "icx": "-qopenmp",
            "apple-clang": "-Xpreprocessor -fopenmp",
            "default": "-fopenmp",
        }),
    EnumOption(
        "layout",
        """The layout of the directory structure. 'standard' installs files to
           several subdirectories under 'prefix', for example, 'prefix/bin',
           'prefix/include/cantera', 'prefix/lib' etc. This layout is best used in
           conjunction with "prefix='/usr/local'". 'compact' puts all installed files
           in the subdirectory defined by 'prefix'. This layout is best with a prefix
           like '/opt/cantera'. 'debian' installs to the stage directory in a layout
           used for generating Debian packages. If the Python executable found during
           compilation is managed by 'conda', the layout will default to 'conda'
           irrespective of operating system. For the 'conda' layout, the Python package
           as well as all libraries and header files are installed into the active
           'conda' environment. Input data, samples, and other files are installed in
           the 'shared/cantera' subdirectory of the active 'conda' environment.""",
        {"Windows": "compact", "default": "standard"},
        ("standard", "compact", "debian", "conda")),
    BoolOption(
        "fast_fail_tests",
        "If enabled, tests will exit at the first failure.",
        False),
    BoolOption(
        "skip_slow_tests",
        """If enabled, skip a subset of tests that are known to have long runtimes.
           Skipping these may be desirable when running with options that cause tests
           to run slowly, like disabling optimization or activating code profiling.""",
        False),
    BoolOption(
        "show_long_tests",
        "If enabled, duration of slowest tests will be shown.",
        False),
    BoolOption(
        "verbose_tests",
        "If enabled, verbose test output will be shown.",
        False),
    BoolOption(
        "legacy_rate_constants",
        """If enabled, rate constant calculations include third-body concentrations
           for three-body reactions, which corresponds to the legacy implementation.
           For Cantera 2.6, the option remains enabled (no change compared to past
           behavior). After Cantera 2.6, the default will be to disable this option,
           and rate constant calculations will be consistent with conventional
           definitions (see Eq. 9.75 in Kee, Coltrin and Glarborg, 'Chemically Reacting
           Flow', Wiley Interscience, 2003).""",
        True),
    BoolOption(
        "no_legacy_reactions",
        """If disabled ('no'/default), legacy 'Reaction' and associated rate objects
           that are deprecated in Cantera 2.6 are used. If enabled ('yes'), internal
           objects will use new objects introduced in Cantera 2.6. The flag is used
           for testing purposes only and has no effect on results.""",
        False),
]

config = Configuration()

if "help" in COMMAND_LINE_TARGETS:
    AddOption(
        "--options", dest="options",
        action="store_true", help="Print description of available options")
    AddOption(
        "--list-options", dest="list",
        action="store_true", help="List available options")
    AddOption(
        "--restructured-text", dest="rest",
        action="store_true", help="Format defaults as reST")
    AddOption(
        "--option", dest="option", nargs=1, type="string",
        action="store", help="Output help for specific option")
    AddOption(
        "--defaults", dest="defaults",
        action="store_true", help="All defaults (CLI only)")
    AddOption(
        "--dev", dest="dev",
        action="store_true", help="Append -dev (reST only)")
    AddOption(
        "--output", dest="output", nargs=1, type="string",
        action="store", help="Output file (reST only)")

    list = GetOption("list")
    rest = GetOption("rest")
    defaults = GetOption("defaults") is not None
    options = GetOption("options")
    option = GetOption("option")

    if not (list or rest or defaults or options or option):
        # show basic help information
        logger.info(__doc__, print_level=False)
        sys.exit(0)

    if defaults or rest or list:

        config.add(windows_options)
        config.add(config_options)

        if list:
            # show formatted list of options
            logger.info("\nConfiguration options for building Cantera:", print_level=False)
            logger.info(config.list_options(), print_level=False)
            sys.exit(0)

        if defaults:
            try:
                # print default values: if option is None, show description for all
                # available options, otherwise show description for specified option
                logger.info(config.help(option), print_level=False)
                sys.exit(0)
            except KeyError as err:
                message = "Run 'scons help --list-options' to see available options."
                logger.error(f"{err}.\n{message}")
                sys.exit(1)

        dev = GetOption("dev") is not None
        try:
            # format default values as reST: if option is None, all descriptions are
            # rendered, otherwise only the description of specified option is shown
            message = config.to_rest(option, dev=dev)
        except KeyError as err:
            message = "Run 'scons help --list-options' to see available options."
            logger.error(f"{err}.\n{message}")
            sys.exit(1)

        output = GetOption("output")
        if output:
            # write output to file
            output_file = Path(output).with_suffix(".rst")
            with open(output_file, "w+") as fid:
                fid.write(message)

            logger.info(f"Done writing output options to '{output_file}'.",
                        print_level=False)

        else:
            logger.info(message, print_level=False)

        sys.exit(0)

# **************************************
# *** Read user-configurable options ***
# **************************************

opts = Variables("cantera.conf")

extraEnvArgs = {}

if os.name == "nt":
    config.add(windows_options)
    config.add(config_options)

    config["prefix"].default = pjoin(os.environ["ProgramFiles"], "Cantera")
    config.select("Windows")

    # On Windows, target the same architecture as the current copy of Python,
    # unless the user specified another option.
    if "64 bit" not in sys.version:
        config["target_arch"].default = "x86"

    opts.AddVariables(*config.to_scons(("msvc_version", "target_arch")))

    windows_compiler_env = Environment()
    opts.Update(windows_compiler_env)

    # Make an educated guess about the right default compiler
    if which("g++") and not which("cl.exe"):
        config["toolchain"].default = "mingw"

    if windows_compiler_env["msvc_version"]:
        config["toolchain"].default = "msvc"

    opts.AddVariables(*config.to_scons("toolchain"))
    opts.Update(windows_compiler_env)

    if windows_compiler_env["toolchain"] == "msvc":
        toolchain = ["default"]
        if windows_compiler_env["msvc_version"]:
            extraEnvArgs["MSVC_VERSION"] = windows_compiler_env["msvc_version"]
        msvc_version = (windows_compiler_env["msvc_version"] or
                        windows_compiler_env["MSVC_VERSION"])
        logger.info(f"Compiling with MSVC {msvc_version}", print_level=False)

    elif windows_compiler_env["toolchain"] == "mingw":
        toolchain = ["mingw", "f90"]
        extraEnvArgs["F77"] = None
        # Next line fixes https://github.com/SCons/scons/issues/2683
        extraEnvArgs["WINDOWS_INSERT_DEF"] = 1

    elif windows_compiler_env["toolchain"] == "intel":
        toolchain = ["intelc"] # note: untested

    extraEnvArgs["TARGET_ARCH"] = windows_compiler_env["target_arch"]
    logger.info(f"Compiling for architecture: {windows_compiler_env['target_arch']}",
        print_level=False)
    logger.info(f"Compiling using the following toolchain(s): {repr(toolchain)}",
        print_level=False)
else:
    config.add(config_options)
    toolchain = ["default"]

env = Environment(tools=toolchain+["textfile", "subst", "recursiveInstall", "wix", "gch"],
                  ENV={"PATH": os.environ["PATH"]},
                  toolchain=toolchain,
                  **extraEnvArgs)

env["OS"] = platform.system()
env["OS_BITS"] = int(platform.architecture()[0][:2])
if "cygwin" in env["OS"].lower():
    env["OS"] = "Cygwin" # remove Windows version suffix

if "FRAMEWORKS" not in env:
    env["FRAMEWORKS"] = []

# Needed for Matlab to source ~/.matlab7rc.sh
if "HOME" in os.environ:
    env["ENV"]["HOME"] = os.environ["HOME"]

if os.name == "nt":
    env["INSTALL_MANPAGES"] = False

    # Fixes a linker error in Windows
    if "TMP" in os.environ:
        env["ENV"]["TMP"] = os.environ["TMP"]

    # Fixes issues with Python subprocesses. See http://bugs.python.org/issue13524
    env["ENV"]["SystemRoot"] = os.environ["SystemRoot"]

    # Fix an issue with Unicode sneaking into the environment on Windows
    for key,val in env["ENV"].items():
        env["ENV"][key] = str(val)

else:
    env["INSTALL_MANPAGES"] = True

add_RegressionTest(env)

opts.AddVariables(*config.to_scons(["CC", "CXX"], env=env))
opts.Update(env)

# Check if this is actually Apple's clang on macOS
env["using_apple_clang"] = False
if env["OS"] == "Darwin":
    result = subprocess.check_output([env.subst("$CC"), "--version"]).decode("utf-8")
    if "clang" in result.lower() and ("Xcode" in result or "Apple" in result):
        env["using_apple_clang"] = True
        config.select("apple-clang")

if "gcc" in env.subst("$CC") or "gnu-cc" in env.subst("$CC"):
    if env["OS"] == "Cygwin":
        config.select("Cygwin")
    config.select("gcc")

elif env["CC"] == "cl": # Visual Studio
    config.select("cl")

elif "icc" in env.subst("$CC"):
    config.select("icc")

elif "icx" in env.subst("$CC"):
    config.select("icx")

elif "clang" in env.subst("$CC"):
    config.select("clang")

else:
    print(f"WARNING: Unrecognized C compiler '{env['CC']}'")

if env["OS"] == "Windows":
    config.select("Windows")
elif env["OS"] == "Darwin":
    config.select("macOS")

# SHLIBVERSION fails with MinGW: http://scons.tigris.org/issues/show_bug.cgi?id=3035
if (env["toolchain"] == "mingw"):
    config.select("mingw")

config.select("default")
config["python_cmd"].default = sys.executable

opts.AddVariables(*config.to_scons())
opts.Update(env)
opts.Save('cantera.conf', env)

# Expand ~/ and environment variables used in cantera.conf (variables used on
# the command line will be expanded by the shell)
for option in opts.keys():
    original = env[option]
    if isinstance(original, str):
        modified = os.path.expandvars(os.path.expanduser(env[option]))
        if original != modified:
            print('INFO: Expanding {!r} to {!r}'.format(original, modified))
            env[option] = modified

if "help" in COMMAND_LINE_TARGETS:
    option = GetOption("option")
    try:
        # print configuration: if option is None, description is shown for all
        # options; otherwise description is shown for specified option
        logger.info(config.help(option, env=env), print_level=False)
        sys.exit(0)
    except KeyError as err:
        message = "Run 'scons help --list-options' to see available options."
        logger.error(f"{err}.\n{message}")
        sys.exit(1)

if 'doxygen' in COMMAND_LINE_TARGETS:
    env['doxygen_docs'] = True
if 'sphinx' in COMMAND_LINE_TARGETS:
    env['sphinx_docs'] = True
if "sdist" in COMMAND_LINE_TARGETS:
    env["python_sdist"] = True

    if env["python_package"] == "default":
        logger.info("'sdist' target was specified. Setting 'python_package' to none.")
        env["python_package"] = "none"
    elif env["python_package"] in ("full", "y"):
        logger.error("'sdist' target was specified. Cannot also build Python package.")
        sys.exit(1)
    for ext_dependency in ("sundials", "fmt", "yamlcpp", "eigen"):
        if env[f"system_{ext_dependency}"] == "y":
            logger.error(f"'sdist' target was specified. Cannot use 'system_{ext_dependency}'.")
            sys.exit(1)
        else:
            env[f"system_{ext_dependency}"] = "n"

    logger.info("'sdist' target was specified. Setting 'use_pch' to False.")
    env["use_pch"] = False

for arg in ARGUMENTS:
    if arg not in config:
        logger.error(f"Encountered unexpected command line option: '{arg}'")
        sys.exit(1)

env["cantera_version"] = "2.6.0b2"
# For use where pre-release tags are not permitted (MSI, sonames)
env['cantera_pure_version'] = re.match(r'(\d+\.\d+\.\d+)', env['cantera_version']).group(0)
env['cantera_short_version'] = re.match(r'(\d+\.\d+)', env['cantera_version']).group(0)

try:
    env["git_commit"] = get_command_output("git", "rev-parse", "--short", "HEAD")
    logger.info(f"Building Cantera from git commit '{env['git_commit']}'")
except (subprocess.CalledProcessError, FileNotFoundError):
    env["git_commit"] = "unknown"

# Print values of all build options:
# the (updated) "cantera.conf" combines all options that were specified by the user
cantera_conf = Path("cantera.conf").read_text()
logger.info("Configuration variables read from 'cantera.conf' and command line:")
logger.info(textwrap.indent(cantera_conf, "    "), print_level=False)

# ********************************************
# *** Configure system-specific properties ***
# ********************************************

# Copy in external environment variables
if env['env_vars'] == 'all':
    env['ENV'].update(os.environ)
    if 'PYTHONHOME' in env['ENV']:
        del env['ENV']['PYTHONHOME']
elif env['env_vars']:
    for name in env['env_vars'].split(','):
        if name in os.environ:
            if name == 'PATH':
                env.AppendENVPath('PATH', os.environ['PATH'])
            else:
                env['ENV'][name] = os.environ[name]
            if env['VERBOSE']:
                print('Propagating environment variable {0}={1}'.format(name, env['ENV'][name]))
        elif name not in config["env_vars"].default.split(','):
            print('WARNING: failed to propagate environment variable', repr(name))
            print('         Edit cantera.conf or the build command line to fix this.')

# @todo: Remove this Warning after Cantera 2.5
if os.pathsep == ';':
    for dirs in (env['extra_inc_dirs'], env['extra_lib_dirs']):
        if re.search(r':\w:', dirs):
            print('ERROR: Multiple entries in "extra_inc_dirs" and "extra_lib_dirs" '
                  'should be separated by semicolons (;) on Windows. Use of OS-specific '
                  'path separator introduced in Cantera 2.5.')
            sys.exit(1)

env['extra_inc_dirs'] = [d for d in env['extra_inc_dirs'].split(os.pathsep) if d]
env['extra_lib_dirs'] = [d for d in env['extra_lib_dirs'].split(os.pathsep) if d]

# Add conda library/include paths (if applicable) to extra
conda_prefix = os.environ.get("CONDA_PREFIX")
if conda_prefix is not None:
    if os.name == "nt":
        conda_inc_dir = pjoin(conda_prefix, "Library", "include")
        conda_lib_dir = pjoin(conda_prefix, "Library", env["libdirname"])
    else:
        conda_inc_dir = pjoin(conda_prefix, "include")
        conda_lib_dir = pjoin(conda_prefix, env["libdirname"])
    env["extra_inc_dirs"].append(conda_inc_dir)
    env["extra_lib_dirs"].append(conda_lib_dir)
    logger.info(f"Adding conda include and library paths: {conda_prefix}")

env.Append(CPPPATH=env['extra_inc_dirs'],
           LIBPATH=env['extra_lib_dirs'])

if env['use_rpath_linkage']:
    env.Append(RPATH=env['extra_lib_dirs'])

if env['CC'] == 'cl':
    # embed manifest file
    env['LINKCOM'] = [env['LINKCOM'],
                      'if exist ${TARGET}.manifest mt.exe -nologo -manifest ${TARGET}.manifest -outputresource:$TARGET;1']
    env['SHLINKCOM'] = [env['SHLINKCOM'],
                        'if exist ${TARGET}.manifest mt.exe -nologo -manifest ${TARGET}.manifest -outputresource:$TARGET;2']
    env['FORTRAN_LINK'] = 'link'
else:
    env['FORTRAN_LINK'] = '$FORTRAN'

if env['boost_inc_dir']:
    env.Append(CPPPATH=env['boost_inc_dir'])

if env['blas_lapack_dir']:
    env.Append(LIBPATH=[env['blas_lapack_dir']])
    if env['use_rpath_linkage']:
        env.Append(RPATH=env['blas_lapack_dir'])

if env['system_sundials'] in ('y','default'):
    if env['sundials_include']:
        env.Append(CPPPATH=[env['sundials_include']])
        env['system_sundials'] = 'y'
    if env['sundials_libdir']:
        env.Append(LIBPATH=[env['sundials_libdir']])
        env['system_sundials'] = 'y'
        if env['use_rpath_linkage']:
            env.Append(RPATH=env['sundials_libdir'])

# BLAS / LAPACK configuration
if env['blas_lapack_libs'] != '':
    env['blas_lapack_libs'] = env['blas_lapack_libs'].split(',')
    env['use_lapack'] = True
elif env['OS'] == 'Darwin':
    env['blas_lapack_libs'] = []
    env['use_lapack'] = True
    env.Append(FRAMEWORKS=['Accelerate'])
else:
    env['blas_lapack_libs'] = []
    env['use_lapack'] = False

# ************************************
# *** Compiler Configuration Tests ***
# ************************************

def CheckStatement(context, function, includes=""):
    context.Message('Checking for %s... ' % function)
    src = """
%(include)s
int main(int argc, char** argv) {
    %(func)s;
    return 0;
}
""" % {'func':function, 'include':includes}
    result = context.TryCompile(src, '.cpp')
    context.Result(result)
    return result

# Set up compiler options before running configuration tests
env['CXXFLAGS'] = listify(env['cxx_flags'])
env['CCFLAGS'] = listify(env['cc_flags']) + listify(env['thread_flags'])
env['LINKFLAGS'] += listify(env['thread_flags'])
env['CPPDEFINES'] = {}

env['warning_flags'] = listify(env['warning_flags'])
env["pch_flags"] = listify(env["pch_flags"])
env["openmp_flag"] = listify(env["openmp_flag"])

if env['optimize']:
    env['CCFLAGS'] += listify(env['optimize_flags'])
    env.Append(CPPDEFINES=['NDEBUG'])
else:
    env['CCFLAGS'] += listify(env['no_optimize_flags'])

if env['debug']:
    env['CCFLAGS'] += listify(env['debug_flags'])
    env['LINKFLAGS'] += listify(env['debug_linker_flags'])
else:
    env['CCFLAGS'] += listify(env['no_debug_flags'])
    env['LINKFLAGS'] += listify(env['no_debug_linker_flags'])

if env['coverage']:
    if  'gcc' in env.subst('$CC') or 'clang' in env.subst('$CC'):
        env.Append(CCFLAGS=['-fprofile-arcs', '-ftest-coverage'])
        env.Append(LINKFLAGS=['-fprofile-arcs', '-ftest-coverage'])

    else:
        print('Error: coverage testing is only available with GCC.')
        exit(0)

if env['toolchain'] == 'mingw':
    env.Append(LINKFLAGS=['-static-libgcc', '-static-libstdc++'])

def config_error(message):
    print('ERROR:', message)
    if env['VERBOSE']:
        print('*' * 25, 'Contents of config.log:', '*' * 25)
        print(open('config.log').read())
        print('*' * 28, 'End of config.log', '*' * 28)
    else:
        print("See 'config.log' for details.")
    sys.exit(1)

conf = Configure(env, custom_tests={'CheckStatement': CheckStatement})
env = conf.env  # Retain updates to `env` after the end of the `Configure` context

# First, a sanity check:
if not conf.CheckCXXHeader("cmath", "<>"):
    config_error(
        "The C++ compiler is not correctly configured (incomplete include paths)."
    )

def get_expression_value(includes, expression, defines=()):
    s = ['#define ' + d for d in defines]
    s.extend('#include ' + i for i in includes)
    s.extend(('#define Q(x) #x',
              '#define QUOTE(x) Q(x)',
              '#include <iostream>',
              '#ifndef SUNDIALS_PACKAGE_VERSION', # name change in Sundials >= 3.0
              '#define SUNDIALS_PACKAGE_VERSION SUNDIALS_VERSION',
              '#endif',
              'int main(int argc, char** argv) {',
              '    std::cout << %s << std::endl;' % expression,
              '    return 0;',
              '}\n'))
    return '\n'.join(s)

# Check that libraries link correctly
cmath_check_source = get_expression_value(["<cmath>"], "cos(0. * argc)")
retcode, cmath_works = conf.TryRun(cmath_check_source, ".cpp")
if cmath_works.strip() != "1":
    config_error(
        "The C++ compiler is not correctly configured (failed at linking stage)."
    )

# Check that NaN is treated correctly
nan_check_source = get_expression_value(["<cmath>"], "std::isnan(NAN + argc)")
retcode, nan_works = conf.TryRun(nan_check_source, ".cpp")
if nan_works.strip() != "1":
    config_error(
        "Cantera requires a working implementation of 'std::isnan'.\n"
        "If you have specified '-ffast-math' or equivalent as an optimization option,\n"
        "either remove this option or add the '-fno-finite-math-only option'."
    )

# Check for fmt library and checkout submodule if needed
# Test for 'ostream.h' to ensure that version >= 3.0.0 is available
if env['system_fmt'] in ('y', 'default'):
    if conf.CheckCXXHeader('fmt/ostream.h', '""'):
        env['system_fmt'] = True
        print("""INFO: Using system installation of fmt library.""")

    elif env['system_fmt'] == 'y':
        config_error('Expected system installation of fmt library, but it '
            'could not be found.')

if env['system_fmt'] in ('n', 'default'):
    env['system_fmt'] = False
    print("""INFO: Using private installation of fmt library.""")
    if not os.path.exists('ext/fmt/include/fmt/ostream.h'):
        if not os.path.exists('.git'):
            config_error('fmt is missing. Install source in ext/fmt.')

        try:
            code = subprocess.call(['git','submodule','update','--init',
                                    '--recursive','ext/fmt'])
        except Exception:
            code = -1
        if code:
            config_error('fmt submodule checkout failed.\n'
                         'Try manually checking out the submodule with:\n\n'
                         '    git submodule update --init --recursive ext/fmt\n')

fmt_include = '<fmt/format.h>' if env['system_fmt'] else '"../ext/fmt/include/fmt/format.h"'
fmt_version_source = get_expression_value([fmt_include], 'FMT_VERSION', ['FMT_HEADER_ONLY'])
retcode, fmt_lib_version = conf.TryRun(fmt_version_source, '.cpp')
try:
    fmt_lib_version = divmod(float(fmt_lib_version.strip()), 10000)
    (fmt_maj, (fmt_min, fmt_pat)) = fmt_lib_version[0], divmod(fmt_lib_version[1], 100)
    env['FMT_VERSION'] = '{major:.0f}.{minor:.0f}.{patch:.0f}'.format(major=fmt_maj, minor=fmt_min, patch=fmt_pat)
    print('INFO: Found fmt version {}'.format(env['FMT_VERSION']))
except ValueError:
    env['FMT_VERSION'] = '0.0.0'
    print('INFO: Could not find version of fmt')

# Check for yaml-cpp library and checkout submodule if needed
if env['system_yamlcpp'] in ('y', 'default'):
    # We need the Mark() function, which was added in version 0.5.3
    if conf.CheckStatement('YAML::Node().Mark()', '#include "yaml-cpp/yaml.h"'):
        env['system_yamlcpp'] = True
        print("""INFO: Using system installation of yaml-cpp library.""")

    elif env['system_yamlcpp'] == 'y':
        config_error("Expected system installation of yaml-cpp library, but it "
            "could not be found or it is too old (0.6 or newer is required).")

if env['system_yamlcpp'] in ('n', 'default'):
    env['system_yamlcpp'] = False
    print("""INFO: Using private installation of yaml-cpp library.""")
    if not os.path.exists('ext/yaml-cpp/include/yaml-cpp/yaml.h'):
        if not os.path.exists('.git'):
            config_error('yaml-cpp is missing. Install source in ext/yaml-cpp.')

        try:
            code = subprocess.call(['git', 'submodule', 'update', '--init',
                                    '--recursive', 'ext/yaml-cpp'])
        except Exception:
            code = -1
        if code:
            config_error('yaml-cpp submodule checkout failed.\n'
                         'Try manually checking out the submodule with:\n\n'
                         '    git submodule update --init --recursive ext/yaml-cpp\n')

# Check for googletest and checkout submodule if needed
if env['googletest'] in ('system', 'default'):
    has_gtest = conf.CheckCXXHeader('gtest/gtest.h', '""')
    has_gmock = conf.CheckCXXHeader('gmock/gmock.h', '""')
    if has_gtest and has_gmock:
        env['googletest'] = 'system'
        print("""INFO: Using system installation of Googletest""")
    elif env['googletest'] == 'system':
        config_error('Expected system installation of Googletest-1.8.0, but it '
                     'could not be found.')

if env['googletest'] in ('submodule', 'default'):
    env['googletest'] = 'submodule'
    has_gtest = os.path.exists('ext/googletest/googletest/include/gtest/gtest.h')
    has_gmock = os.path.exists('ext/googletest/googlemock/include/gmock/gmock.h')
    if not (has_gtest and has_gmock):
        if not os.path.exists('.git'):
            config_error('Googletest is missing. Install source in ext/googletest.')

        try:
            code = subprocess.call(['git','submodule','update','--init',
                                    '--recursive','ext/googletest'])
        except Exception:
            code = -1
        if code:
            config_error('Googletest not found and submodule checkout failed.\n'
                         'Try manually checking out the submodule with:\n\n'
                         '    git submodule update --init --recursive ext/googletest\n')
    print("""INFO: Using Googletest from Git submodule""")

if env['googletest'] == 'none':
    print("""INFO: Not using Googletest -- unable to run complete test suite""")

# Check for Eigen and checkout submodule if needed
if env["system_eigen"] in ("y", "default"):
    if conf.CheckCXXHeader("eigen3/Eigen/Dense", "<>"):
        env["system_eigen"] = True
        env["system_eigen_prefixed"] = True
        print("""INFO: Using system installation of Eigen.""")
        eigen_include = "<eigen3/Eigen/Core>"
    elif conf.CheckCXXHeader("Eigen/Dense", "<>"):
        env["system_eigen"] = True
        env["system_eigen_prefixed"] = False
        print("""INFO: Using system installation of Eigen.""")
        eigen_include = "<Eigen/Core>"
    elif env["system_eigen"] == "y":
        config_error("Expected system installation of Eigen, but it "
                     "could not be found.")

if env["system_eigen"] in ("n", "default"):
    env["system_eigen"] = False
    print("""INFO: Using private installation of Eigen.""")
    if not os.path.exists("ext/eigen/Eigen/Dense"):
        if not os.path.exists(".git"):
            config_error("Eigen is missing. Install Eigen in ext/eigen.")

        try:
            code = subprocess.call(["git","submodule","update","--init",
                                    "--recursive","ext/eigen"])
        except Exception:
            code = -1
        if code:
            config_error("Eigen not found and submodule checkout failed.\n"
                         "Try manually checking out the submodule with:\n\n"
                         "    git submodule update --init --recursive ext/eigen\n")
    eigen_include = "'../ext/eigen/Eigen/Core'"

eigen_versions = 'QUOTE(EIGEN_WORLD_VERSION) "." QUOTE(EIGEN_MAJOR_VERSION) "." QUOTE(EIGEN_MINOR_VERSION)'
eigen_version_source = get_expression_value([eigen_include], eigen_versions)
retcode, eigen_lib_version = conf.TryRun(eigen_version_source, ".cpp")
env["EIGEN_LIB_VERSION"] = eigen_lib_version.strip()
print("INFO: Found Eigen version {}".format(env["EIGEN_LIB_VERSION"]))

# Determine which standard library to link to when using Fortran to
# compile code that links to Cantera
if conf.CheckDeclaration('__GLIBCXX__', '#include <iostream>', 'C++'):
    env['cxx_stdlib'] = ['stdc++']
elif conf.CheckDeclaration('_LIBCPP_VERSION', '#include <iostream>', 'C++'):
    env['cxx_stdlib'] = ['c++']
else:
    env['cxx_stdlib'] = []

env['HAS_CLANG'] = conf.CheckDeclaration('__clang__', '', 'C++')
if not env["using_apple_clang"]:
    # This checks for these three libraries in order and stops when it finds the
    # first success. Intel = iomp5, LLVM/clang = omp, GCC = gomp. Since gomp is
    # likely to be installed on the system even if other compilers are installed
    # or in use, it needs to go last in the check.
    env['HAS_OPENMP'] = conf.CheckLibWithHeader(
        ["iomp5", "omp", "gomp"], "omp.h", language="C++"
    )
else:
    env["HAS_OPENMP"] = False
    logger.info("Not checking for OpenMP support due to using XCode compiler.")

boost_version_source = get_expression_value(['<boost/version.hpp>'], 'BOOST_LIB_VERSION')
retcode, boost_lib_version = conf.TryRun(boost_version_source, '.cpp')
env['BOOST_LIB_VERSION'] = '.'.join(boost_lib_version.strip().split('_'))
if not env['BOOST_LIB_VERSION']:
    config_error("Boost could not be found. Install Boost headers or set"
                 " 'boost_inc_dir' to point to the boost headers.")
else:
    print('INFO: Found Boost version {0}'.format(env['BOOST_LIB_VERSION']))
# demangle is available in Boost 1.56 or newer
env['has_demangle'] = conf.CheckDeclaration("boost::core::demangle",
                                '#include <boost/core/demangle.hpp>', 'C++')

import SCons.Conftest, SCons.SConf
context = SCons.SConf.CheckContext(conf)

cvode_checks = [
    "CVodeCreate(CV_BDF, CV_NEWTON);",  # Sundials <= 3.2
    "CVodeCreate(CV_BDF);",  # Sundials>=4.0,<6.0
    "SUNContext ctx; SUNContext_Create(0, &ctx);"  # Sundials>=6.0
]
for cvode_call in cvode_checks:
    ret = SCons.Conftest.CheckLib(context,
                                  ['sundials_cvodes'],
                                  header='#include "cvodes/cvodes.h"',
                                  language='C++',
                                  call=cvode_call,
                                  autoadd=False,
                                  extra_libs=env['blas_lapack_libs'])
    # CheckLib returns False to indicate success
    if not ret:
        if env['system_sundials'] == 'default':
            env['system_sundials'] = 'y'
        break

# Execute if the cycle ends without 'break'
else:
    if env['system_sundials'] == 'default':
        env['system_sundials'] = 'n'
    elif env['system_sundials'] == 'y':
        config_error('Expected system installation of Sundials, but it could '
                     'not be found.')

# Checkout Sundials submodule if needed
if (env['system_sundials'] == 'n' and
    not os.path.exists('ext/sundials/include/cvodes/cvodes.h')):
    if not os.path.exists('.git'):
        config_error('Sundials is missing. Install source in ext/sundials.')

    try:
        code = subprocess.call(['git','submodule','update','--init',
                                '--recursive','ext/sundials'])
    except Exception:
        code = -1
    if code:
        config_error('Sundials not found and submodule checkout failed.\n'
                     'Try manually checking out the submodule with:\n\n'
                     '    git submodule update --init --recursive ext/sundials\n')


env['NEED_LIBM'] = not conf.CheckLibWithHeader(None, 'math.h', 'C',
                                               'double x; log(x);', False)
env['LIBM'] = ['m'] if env['NEED_LIBM'] else []

if env['system_sundials'] == 'y':
    for subdir in ('sundials', 'nvector', 'cvodes', 'ida', 'sunlinsol', 'sunmatrix'):
        remove_directory('include/cantera/ext/' + subdir)

    # Determine Sundials version
    sundials_version_source = get_expression_value(['"sundials/sundials_config.h"'],
                                                   'QUOTE(SUNDIALS_PACKAGE_VERSION)')
    retcode, sundials_version = conf.TryRun(sundials_version_source, '.cpp')
    if retcode == 0:
        config_error("Failed to determine Sundials version.")
    sundials_version = sundials_version.strip(' "\n')

    # Ignore the minor version, e.g. 2.4.x -> 2.4
    env['sundials_version'] = '.'.join(sundials_version.split('.')[:2])
    sundials_ver = parse_version(env['sundials_version'])
    if sundials_ver < parse_version("2.4") or sundials_ver >= parse_version("7.0"):
        print("""ERROR: Sundials version %r is not supported.""" % env['sundials_version'])
        sys.exit(1)
    elif sundials_ver > parse_version("6.0"):
        print("WARNING: Sundials version %r has not been tested." % env['sundials_version'])

    print("""INFO: Using system installation of Sundials version %s.""" % sundials_version)

    # Determine whether or not Sundials was built with BLAS/LAPACK
    if sundials_ver < parse_version('2.6'):
        # In Sundials 2.4 / 2.5, SUNDIALS_BLAS_LAPACK is either 0 or 1
        sundials_blas_lapack = get_expression_value(['"sundials/sundials_config.h"'],
                                                       'SUNDIALS_BLAS_LAPACK')
        retcode, has_sundials_lapack = conf.TryRun(sundials_blas_lapack, '.cpp')
        if retcode == 0:
            config_error("Failed to determine Sundials BLAS/LAPACK.")
        env['has_sundials_lapack'] = int(has_sundials_lapack.strip())
    elif sundials_ver < parse_version('5.5'):
        # In Sundials 2.6-5.5, SUNDIALS_BLAS_LAPACK is either defined or undefined
        env['has_sundials_lapack'] = conf.CheckDeclaration('SUNDIALS_BLAS_LAPACK',
                '#include "sundials/sundials_config.h"', 'C++')
    else:
        # In Sundials 5.5 and higher, two defines are included specific to the
        # SUNLINSOL packages indicating whether SUNDIALS has been built with LAPACK
        lapackband = conf.CheckDeclaration(
            "SUNDIALS_SUNLINSOL_LAPACKBAND",
            '#include "sundials/sundials_config.h"',
            "C++",
        )
        lapackdense = conf.CheckDeclaration(
            "SUNDIALS_SUNLINSOL_LAPACKDENSE",
            '#include "sundials/sundials_config.h"',
            "C++",
        )
        env["has_sundials_lapack"] = lapackband and lapackdense

    # In the case where a user is trying to link Cantera to an external BLAS/LAPACK
    # library, but Sundials was configured without this support, print a Warning.
    if not env['has_sundials_lapack'] and env['use_lapack']:
        print('WARNING: External BLAS/LAPACK has been specified for Cantera '
              'but Sundials was built without this support.')
else: # env['system_sundials'] == 'n'
    print("""INFO: Using private installation of Sundials version 5.3.""")
    env['sundials_version'] = '5.3'
    env['has_sundials_lapack'] = int(env['use_lapack'])

def set_fortran(pattern, value):
    # Set compiler / flags for all Fortran versions to be the same
    for version in ("FORTRAN", "F77", "F90", "F95", "F03", "F08"):
        env[pattern.format(version)] = value

# Try to find a working Fortran compiler:
def check_fortran(compiler, expected=False):
    hello_world = '''
program main
   write(*,'(a)') 'Hello, world!'
end program main
    '''
    if which(compiler):
        set_fortran("{}", compiler)
        success, output = conf.TryRun(hello_world, '.f90')
        if success and 'Hello, world!' in output:
            return True
        else:
            print("WARNING: Unable to use '%s' to compile the Fortran "
                  "interface. See config.log for details." % compiler)
            return False
    elif expected:
        print("ERROR: Couldn't find specified Fortran compiler: '%s'" % compiler)
        sys.exit(1)

    return False

set_fortran("{}FLAGS", env["FORTRANFLAGS"])

if env['f90_interface'] in ('y','default'):
    foundF90 = False
    if env['FORTRAN']:
        foundF90 = check_fortran(env['FORTRAN'], True)

    for compiler in ("pgfortran", "gfortran", "ifort", "ifx", "g95"):
        if foundF90:
            break
        foundF90 = check_fortran(compiler)

    if foundF90:
        print("INFO: Using '%s' to build the Fortran 90 interface" % env['FORTRAN'])
        env['f90_interface'] = 'y'
    else:
        if env['f90_interface'] == 'y':
            print("ERROR: Couldn't find a suitable Fortran compiler to build the Fortran 90 interface.")
            sys.exit(1)
        else:
            env['f90_interface'] = 'n'
            env['FORTRAN'] = ''
            print("INFO: Skipping compilation of the Fortran 90 interface.")

if 'pgfortran' in env['FORTRAN']:
    env['FORTRANMODDIRPREFIX'] = '-module '
elif 'gfortran' in env['FORTRAN']:
    env['FORTRANMODDIRPREFIX'] = '-J'
elif 'g95' in env['FORTRAN']:
    env['FORTRANMODDIRPREFIX'] = '-fmod='
elif 'ifort' in env['FORTRAN']:
    env['FORTRANMODDIRPREFIX'] = '-module '
elif "ifx" in env["FORTRAN"]:
    env["FORTRANMODDIRPREFIX"] = "-module "

set_fortran("{}", env["FORTRAN"])
set_fortran("SH{}", env["FORTRAN"])
env['FORTRANMODDIR'] = '${TARGET.dir}'

env = conf.Finish()

if env['VERBOSE']:
    print('-------------------- begin config.log --------------------')
    print(open('config.log').read())
    print('--------------------- end config.log ---------------------')

env['python_cmd_esc'] = quoted(env['python_cmd'])

# Python Package Settings
python_min_version = parse_version("3.7")
# The string is used to set python_requires in setup.cfg.in
env['py_min_ver_str'] = str(python_min_version)
# Note: cython_min_version is redefined below if the Python version is 3.8 or higher
cython_min_version = parse_version('0.23')
numpy_min_version = parse_version('1.12.0')

# We choose ruamel.yaml 0.15.34 as the minimum version
# since it is the highest version available in the Ubuntu
# 18.04 repositories and seems to work. Older versions such as
# 0.13.14 on CentOS7 and 0.10.23 on Ubuntu 16.04 raise an exception
# that they are missing the RoundTripRepresenter
ruamel_min_version = parse_version('0.15.34')

# Check for the minimum ruamel.yaml version, 0.15.34, at install and test
# time. The check happens at install and test time because ruamel.yaml is
# only required to run the Python interface, not to build it.
check_for_ruamel_yaml = any(
    target in COMMAND_LINE_TARGETS
    for target in ["install", "test", "test-python-convert"]
)

if env['python_package'] == 'y':
    env['python_package'] = 'full'  # Allow 'y' as a synonym for 'full'
elif env['python_package'] == 'n':
  env['python_package'] = 'none'  # Allow 'n' as a synonym for 'none'

env['install_python_action'] = ''
env['python_module_loc'] = ''
env["ct_pyscriptdir"] = "<not installed>"

if env['python_package'] != 'none':
    # Test to see if we can import numpy and Cython
    script = textwrap.dedent("""\
        import sys
        print('{v.major}.{v.minor}'.format(v=sys.version_info))
        err = ''
        try:
            import numpy
            print(numpy.__version__)
        except ImportError as np_err:
            print('0.0.0')
            err += str(np_err) + '\\n'
        try:
            import Cython
            print(Cython.__version__)
        except ImportError as cython_err:
            print('0.0.0')
            err += str(cython_err) + '\\n'
        if err:
            print(err)
    """)
    expected_output_lines = 3
    if check_for_ruamel_yaml:
        ru_script = textwrap.dedent("""\
            try:
                from ruamel import yaml
                print(yaml.__version__)
            except ImportError as ru_err:
                try:
                    import ruamel_yaml as yaml
                    print(yaml.__version__)
                except ImportError as ru_err_2:
                    print('0.0.0')
                    err += str(ru_err) + '\\n'
                    err += str(ru_err_2) + '\\n'
        """).splitlines()
        s = script.splitlines()
        s[-2:-2] = ru_script
        script = "\n".join(s)
        expected_output_lines = 4

    try:
        info = get_command_output(env["python_cmd"], "-c", script).splitlines()
    except OSError as err:
        if env['VERBOSE']:
            print('Error checking for Python:')
            print(err)
        warn_no_python = True
    except subprocess.CalledProcessError as err:
        if env['VERBOSE']:
            print('Error checking for Python:')
            print(err, err.output)
        warn_no_python = True
    else:
        warn_no_python = False
        python_version = parse_version(info[0])
        numpy_version = parse_version(info[1])
        cython_version = parse_version(info[2])
        if check_for_ruamel_yaml:
            ruamel_yaml_version = parse_version(info[3])
            if ruamel_yaml_version == parse_version("0.0.0"):
                logger.error(
                    f"ruamel.yaml was not found. {ruamel_min_version} or newer "
                    "is required.")
                sys.exit(1)
            elif ruamel_yaml_version < ruamel_min_version:
                logger.error(
                    "ruamel.yaml is an incompatible version: Found "
                    f"{ruamel_yaml_version}, but {ruamel_min_version} or newer "
                    "is required.")
                sys.exit(1)

    if warn_no_python:
        if env["python_package"] == "default":
            logger.warning(
                "Not building the Python package because the Python interpreter "
                f"'{env['python_cmd']!r}' could not be found.")
            env["python_package"] = "none"
        else:
            logger.error(
                f"Could not execute the Python interpreter '{env['python_cmd']!r}'")
            sys.exit(1)
    elif python_version < python_min_version:
        if env["python_package"] in ("minimal", "full", "default"):
            logger.error(
                f"Python version is incompatible. Found {python_version} but "
                f"{python_min_version} or newer is required. In order to install "
                "Cantera without Python support, specify 'python_package=none'.")
            sys.exit(1)
    elif env["python_package"] == "minimal":
        # If the minimal package was specified, no further checking needs to be done
        logger.info(f"Building the minimal Python package for Python {python_version}")
    else:

        if len(info) > expected_output_lines:
            msg = ["Unexpected output while checking Python dependency versions:"]
            msg.extend(info[expected_output_lines:])
            logger.warning("\n| ".join(msg))

        warn_no_full_package = False
        if python_version >= parse_version("3.8"):
            # Reset the minimum Cython version if the Python version is 3.8 or higher
            # Due to internal changes in the CPython API, more recent versions of
            # Cython are necessary to build for Python 3.8. There is nothing Cantera
            # can do about this, the changes in CPython are handled by Cython. This
            # version bump is used to produce a more useful/actionable error message
            # for users than the compilation errors that result from using
            # Cython < 0.29.12.
            cython_min_version = parse_version("0.29.12")

        if numpy_version == parse_version("0.0.0"):
            logger.info("NumPy not found.")
            warn_no_full_package = True
        elif numpy_version < numpy_min_version:
            logger.warning(
                f"NumPy is an incompatible version: Found {numpy_version} but "
                f"{numpy_min_version} or newer is required.")
            warn_no_full_package = True
        else:
            logger.info(f"Using NumPy version {numpy_version}")

        if cython_version == parse_version("0.0.0"):
            logger.info("Cython not found.")
            warn_no_full_package = True
        elif cython_version < cython_min_version:
            lopgger.warning(
                f"Cython is an incompatible version: Found {cython_version} but "
                f"{cython_min_version} or newer is required.")
            warn_no_full_package = True
        else:
            logger.info(f"Using Cython version {cython_version}")

        if warn_no_full_package:
            msg = ("Unable to build the full Python package because compatible "
                   "versions of Numpy and/or Cython could not be found.")
            if env["python_package"] == "default":
                logger.warning(msg)
                logger.info(
                    f"Building the minimal Python package for Python {python_version}")
                env["python_package"] = "minimal"
            else:
                logger.error(msg)
                sys.exit(1)
        else:
            logger.info(
                f"Building the full Python package for Python {python_version}")
            env["python_package"] = "full"

if env["python_package"] == "full" and env["OS"] == "Darwin":
    # We need to know the macOS deployment target in advance to be able to determine
    # the name of the wheel file for the Python module. If this is not specified by the
    # MACOSX_DEPLOYMENT_TARGET environment variable, get the value from the Python
    # installation and use that.
    if not env["ENV"].get("MACOSX_DEPLOYMENT_TARGET", False):
        info = get_command_output(
            env["python_cmd"],
            "-c",
            "import sysconfig; print(sysconfig.get_platform())"
        )
        env["ENV"]["MACOSX_DEPLOYMENT_TARGET"] = info.split("-")[1]

# Matlab Toolbox settings
if env["matlab_path"] != "" and env["matlab_toolbox"] == "default":
    env["matlab_toolbox"] = "y"

if env["matlab_toolbox"] == "y":
    matlab_path = env["matlab_path"]
    if matlab_path == "":
        logger.error(
            "Unable to build the Matlab toolbox because 'matlab_path' "
            "has not been set.")
        sys.exit(1)

    if env['blas_lapack_libs']:
        logger.error(
            "The Matlab toolbox is incompatible with external BLAS "
            "and LAPACK libraries. Unset blas_lapack_libs (e.g. 'scons "
            "build blas_lapack_libs=') in order to build the Matlab "
            "toolbox, or set 'matlab_toolbox=n' to use the specified BLAS/"
            "LAPACK libraries and skip building the Matlab toolbox.")
        sys.exit(1)

    if env["system_sundials"] == "y":
        logger.error(
            "The Matlab toolbox is incompatible with external SUNDIALS "
            "libraries. Set system_sundials to no (e.g., 'scons build "
            "system_sundials=n') in order to build the Matlab "
            "toolbox, or set 'matlab_toolbox=n' to use the specified "
            "SUNDIALS libraries and skip building the Matlab toolbox.")
        sys.exit(1)

    if not (os.path.isdir(matlab_path) and
            os.path.isdir(pjoin(matlab_path, "extern"))):
        logger.error(
            f"Path set for 'matlab_path' is not correct. Path was '{matlab_path}'")
        sys.exit(1)


# **********************************************
# *** Set additional configuration variables ***
# **********************************************

# On Debian-based systems, need to special-case installation to
# /usr/local because of dist-packages vs site-packages
env['debian'] = any(name.endswith('dist-packages') for name in sys.path)

# Identify options selected either on command line or in cantera.conf
selected_options = set(line.split("=")[0].strip()
    for line in cantera_conf.splitlines())

# Always set the stage directory before building an MSI installer
if "msi" in COMMAND_LINE_TARGETS:
    COMMAND_LINE_TARGETS.append("install")
    env["stage_dir"] = "stage"
    env["prefix"] = "."
    selected_options.add("prefix")
    selected_options.add("stage_dir")
    env["python_package"] = "none"
elif env["layout"] == "debian":
    COMMAND_LINE_TARGETS.append("install")
    env["stage_dir"] = "stage/cantera"
    env["PYTHON_INSTALLER"] = "debian"
    env["INSTALL_MANPAGES"] = False
else:
    env["PYTHON_INSTALLER"] = "direct"

env["default_prefix"] = True
if "prefix" in selected_options:
    env["default_prefix"] = False

# Check whether Cantera should be installed into a conda environment
if conda_prefix is not None and sys.executable.startswith(conda_prefix):
    # use conda layout unless any 'blocking' options were specified
    blocking_options = {"layout", "prefix", "python_prefix", "python_cmd"}
    if not selected_options & blocking_options:
        env["layout"] = "conda"
        # Directories where things will be after actually being installed. These
        # variables are the ones that are used to populate header files, scripts,
        # etc.
        conda_prefix = Path(conda_prefix)
        if "stage_dir" in selected_options:
            env["prefix"] = str(conda_prefix.relative_to(conda_prefix.parents[2]))
        else:
            env["prefix"] = str(conda_prefix.resolve())
        logger.info(
            f"Using conda environment as default 'prefix': {env['prefix']}")
elif env["layout"] == "conda":
    logger.error("Layout option 'conda' requires a conda environment.")
    sys.exit(1)

if env["layout"] == "conda" and os.name == "nt":
    env["ct_libdir"] = pjoin(env["prefix"], "Library", env["libdirname"])
    env["ct_bindir"] = pjoin(env["prefix"], "Scripts")
    env["ct_python_bindir"] = pjoin(env["prefix"], "Scripts")
    env["ct_incdir"] = pjoin(env["prefix"], "Library", "include", "cantera")
    env["ct_incroot"] = pjoin(env["prefix"], "Library", "include")
else:
    if "stage_dir" not in selected_options:
        env["prefix"] = str(Path(env["prefix"]).resolve())
    env["ct_libdir"] = pjoin(env["prefix"], env["libdirname"])
    env["ct_bindir"] = pjoin(env["prefix"], "bin")
    env["ct_python_bindir"] = pjoin(env["prefix"], "bin")
    env["ct_incdir"] = pjoin(env["prefix"], "include", "cantera")
    env["ct_incroot"] = pjoin(env["prefix"], "include")

env["ct_installroot"] = env["prefix"]

# Remove back slashes from paths. For example, C:\Users results in a Unicode error
# because \U is the prefix for a Unicode sequence. This kind of thing can happen
# on other platforms too, so this replacement isn't conditional.
env["prefix"] = env["prefix"].replace("\\", "/")

if env['layout'] == 'compact':
    env['ct_datadir'] = pjoin(env['prefix'], 'data')
    env['ct_sampledir'] = pjoin(env['prefix'], 'samples')
    env["ct_docdir"] = pjoin(env["prefix"], "doc")
    env['ct_mandir'] = pjoin(env['prefix'], 'man1')
    env['ct_matlab_dir'] = pjoin(env['prefix'], 'matlab', 'toolbox')
else:
    env['ct_datadir'] = pjoin(env['prefix'], 'share', 'cantera', 'data')
    env['ct_sampledir'] = pjoin(env['prefix'], 'share', 'cantera', 'samples')
    env["ct_docdir"] = pjoin(env["prefix"], "share", "cantera", "doc")
    env['ct_mandir'] = pjoin(env['prefix'], 'share', 'man', 'man1')
    if env["layout"] == "conda":
        env["ct_matlab_dir"] = pjoin(
            env["prefix"], "share", "cantera", "matlab", "toolbox")
    else:
        env["ct_matlab_dir"] = pjoin(
            env["prefix"], env["libdirname"], "cantera", "matlab", "toolbox")


addInstallActions = ('install' in COMMAND_LINE_TARGETS or
                     'uninstall' in COMMAND_LINE_TARGETS)

# Directories where things will be staged for package creation. These
# variables should always be used by the Install(...) targets
if env["stage_dir"]:
    stage_prefix = Path(env["prefix"])
    # Strip the root off the prefix if it's absolute
    if stage_prefix.is_absolute():
        stage_prefix = Path(*stage_prefix.parts[1:])

    instRoot = str(Path.cwd().joinpath(env["stage_dir"], stage_prefix))
else:
    instRoot = env["prefix"]

# Prevent setting Cantera installation path to source directory
if os.path.abspath(instRoot) == Dir('.').abspath:
    print('ERROR: cannot install Cantera into source directory.')
    exit(1)

if env['layout'] == 'debian':
    base = pjoin(os.getcwd(), 'debian')
    env["inst_root"] = base

    env['inst_libdir'] = pjoin(base, 'cantera-dev', 'usr', env['libdirname'])
    env['inst_incdir'] = pjoin(base, 'cantera-dev', 'usr', 'include', 'cantera')
    env['inst_incroot'] = pjoin(base, 'cantera-dev', 'usr' 'include')

    env['inst_bindir'] = pjoin(base, 'cantera-common', 'usr', 'bin')
    env['inst_datadir'] = pjoin(base, 'cantera-common', 'usr', 'share', 'cantera', 'data')
    env['inst_docdir'] = pjoin(base, 'cantera-common', 'usr', 'share', 'cantera', 'doc')
    env['inst_sampledir'] = pjoin(base, 'cantera-common', 'usr', 'share', 'cantera', 'samples')
    env['inst_mandir'] = pjoin(base, 'cantera-common', 'usr', 'share', 'man', 'man1')

    env['inst_matlab_dir'] = pjoin(base, 'cantera-matlab', 'usr',
                                   env['libdirname'], 'cantera', 'matlab', 'toolbox')

    env['inst_python_bindir'] = pjoin(base, 'cantera-python', 'usr', 'bin')
    env['python_prefix'] = pjoin(base, 'cantera-python3')
else:
    env["inst_root"] = instRoot
    locations = ["libdir", "bindir", "python_bindir", "incdir", "incroot",
        "matlab_dir", "datadir", "sampledir", "docdir", "mandir"]
    for loc in locations:
        env[f"inst_{loc}"] = env[f"ct_{loc}"].replace(env["ct_installroot"], instRoot)

# **************************************
# *** Set options needed in config.h ***
# **************************************

configh = {}

configh['CANTERA_VERSION'] = quoted(env['cantera_version'])
configh['CANTERA_SHORT_VERSION'] = quoted(env['cantera_short_version'])

# Conditional defines
def cdefine(definevar, configvar, comp=True, value=1):
    if env.get(configvar) == comp:
        configh[definevar] = value
    else:
        configh[definevar] = None

# Need to test all of these to see what platform.system() returns
configh['SOLARIS'] = 1 if env['OS'] == 'Solaris' else None
configh['DARWIN'] = 1 if env['OS'] == 'Darwin' else None

if env['OS'] == 'Solaris' or env['HAS_CLANG']:
    env["RPATHPREFIX"] = "-Wl,-rpath,"

if env["OS"] == "Darwin" and env["use_rpath_linkage"] and not env.subst("$__RPATH"):
    # SCons doesn't want to specify RPATH on macOS, so circumvent that behavior by
    # specifying this directly as part of LINKFLAGS
    env.Append(LINKFLAGS=[env.subst(f'$RPATHPREFIX{x}$RPATHSUFFIX')
                          for x in env['RPATH']])

configh['CT_SUNDIALS_VERSION'] = env['sundials_version'].replace('.','')

if env.get('has_sundials_lapack') and env['use_lapack']:
    configh['CT_SUNDIALS_USE_LAPACK'] = 1
else:
    configh['CT_SUNDIALS_USE_LAPACK'] = 0

if env['legacy_rate_constants']:
    configh['CT_LEGACY_RATE_CONSTANTS'] = 1
else:
    configh['CT_LEGACY_RATE_CONSTANTS'] = 0

cdefine('LAPACK_FTN_STRING_LEN_AT_END', 'lapack_ftn_string_len_at_end')
cdefine('LAPACK_FTN_TRAILING_UNDERSCORE', 'lapack_ftn_trailing_underscore')
cdefine('FTN_TRAILING_UNDERSCORE', 'lapack_ftn_trailing_underscore')
cdefine('LAPACK_NAMES_LOWERCASE', 'lapack_names', 'lower')
cdefine('CT_USE_LAPACK', 'use_lapack')
cdefine("CT_USE_SYSTEM_EIGEN", "system_eigen")
cdefine("CT_USE_SYSTEM_EIGEN_PREFIXED", "system_eigen_prefixed")
cdefine('CT_USE_SYSTEM_FMT', 'system_fmt')
cdefine('CT_USE_SYSTEM_YAMLCPP', 'system_yamlcpp')
cdefine('CT_USE_DEMANGLE', 'has_demangle')
cdefine("CT_NO_LEGACY_REACTIONS_26", "no_legacy_reactions")

config_h_build = env.Command('build/src/config.h.build',
                             'include/cantera/base/config.h.in',
                       ConfigBuilder(configh))
# This separate copy operation, which SCons will skip if config.h.build is
# unmodified, prevents unnecessary rebuilds of the precompiled header
config_h = env.Command('include/cantera/base/config.h',
                       'build/src/config.h.build',
                       Copy('$TARGET', '$SOURCE'))
env.AlwaysBuild(config_h_build)
env['config_h_target'] = config_h

# *********************
# *** Build Cantera ***
# *********************

# Some options to speed up SCons
env.SetOption('max_drift', 2)
env.SetOption('implicit_cache', True)

buildTargets = []
env['build_targets'] = buildTargets
libraryTargets = [] # objects that go in the Cantera library
installTargets = []
sampleTargets = []

def build(targets):
    """ Wrapper to add target to list of build targets """
    buildTargets.extend(targets)
    return targets

def buildSample(*args, **kwargs):
    """ Wrapper to add target to list of samples """
    targets = args[0](*args[1:], **kwargs)
    sampleTargets.extend(targets)
    return targets

def install(*args, **kwargs):
    """ Wrapper to add target to list of install targets """
    if not addInstallActions:
        return
    if len(args) == 2:
        inst = env.Install(*args, **kwargs)
    else:
        inst = args[0](*args[1:], **kwargs)

    installTargets.extend(inst)
    return inst


env.SConsignFile()

env.Prepend(CPPPATH=[],
           LIBPATH=[Dir('build/lib')])

# preprocess input files (cti -> xml)
convertedInputFiles = set()
convertEnv = env.Clone()
convertEnv["ENV"]["CT_NO_XML_WARNINGS"] = "1"
for cti in multi_glob(env, 'data/inputs', 'cti'):
    build(convertEnv.Command('build/data/%s' % cti.name, cti.path,
                             Copy('$TARGET', '$SOURCE')))
    outName = os.path.splitext(cti.name)[0] + '.xml'
    convertedInputFiles.add(outName)
    build(convertEnv.Command(
        'build/data/%s' % outName, cti.path,
        '$python_cmd_esc interfaces/cython/cantera/ctml_writer.py $SOURCE $TARGET'))

# Copy XML input files which are not present as cti:
for xml in multi_glob(env, 'data/inputs', 'xml'):
    dest = pjoin('build','data',xml.name)
    if xml.name not in convertedInputFiles:
        build(env.Command(dest, xml.path, Copy('$TARGET', '$SOURCE')))

for yaml in multi_glob(env, "data", "yaml"):
    dest = pjoin("build", "data", yaml.name)
    build(env.Command(dest, yaml.path, Copy("$TARGET", "$SOURCE")))
for subdir in os.listdir('data'):
    if os.path.isdir(pjoin('data', subdir)):
        for yaml in multi_glob(env, pjoin("data", subdir), "yaml"):
            dest = pjoin("build", "data", subdir, yaml.name)
            if not os.path.exists(pjoin("build", "data", subdir)):
                os.makedirs(pjoin("build", "data", subdir))
            build(env.Command(dest, yaml.path, Copy("$TARGET", "$SOURCE")))


if addInstallActions:
    # Put headers in place
    headerBase = 'include/cantera'
    install(env.RecursiveInstall, '$inst_incdir', 'include/cantera')

    # Data files
    install(env.RecursiveInstall, '$inst_datadir', 'build/data')


if env['system_sundials'] == 'y':
    env['sundials_libs'] = ['sundials_cvodes', 'sundials_ida', 'sundials_nvecserial']
    if env['use_lapack'] and sundials_ver >= parse_version('3.0'):
        if env.get('has_sundials_lapack'):
            env['sundials_libs'].extend(('sundials_sunlinsollapackdense',
                                         'sundials_sunlinsollapackband'))
        else:
            env['sundials_libs'].extend(('sundials_sunlinsoldense',
                                         'sundials_sunlinsolband'))
else:
    env['sundials_libs'] = []

# External libraries to link to
env["external_libs"] = []
env["external_libs"].extend(env["sundials_libs"])

if env["system_fmt"]:
    env["external_libs"].append("fmt")

if env["system_yamlcpp"]:
    env["external_libs"].append("yaml-cpp")

if env["blas_lapack_libs"]:
    env["external_libs"].extend(env["blas_lapack_libs"])

# List of static libraries needed to link to Cantera
env["cantera_libs"] = ["cantera"] + env["external_libs"]

# List of shared libraries needed to link to Cantera
if env["renamed_shared_libraries"]:
    env["cantera_shared_libs"] = ["cantera_shared"] + env["external_libs"]
else:
    env["cantera_shared_libs"] = ["cantera"] + env["external_libs"]

# Add targets from the SConscript files in the various subdirectories
Export('env', 'build', 'libraryTargets', 'install', 'buildSample', "configh")

# ext needs to come before src so that libraryTargets is fully populated
VariantDir('build/ext', 'ext', duplicate=0)
SConscript('build/ext/SConscript')

# Fortran needs to come before src so that libraryTargets is fully populated
if env['f90_interface'] == 'y':
    VariantDir('build/src/fortran/', 'src/fortran', duplicate=1)
    SConscript('build/src/fortran/SConscript')

VariantDir('build/src', 'src', duplicate=0)
SConscript('build/src/SConscript')

if env["python_package"] == "full":
    VariantDir("build/python", "interfaces/cython", duplicate=True)
    SConscript("build/python/SConscript")
elif env["python_package"] == "minimal":
    VariantDir("build/python_minimal", "interfaces/python_minimal", duplicate=True)
    SConscript("build/python_minimal/SConscript")

if env['CC'] != 'cl':
    VariantDir('build/platform', 'platform/posix', duplicate=0)
    SConscript('build/platform/SConscript')

if env['matlab_toolbox'] == 'y':
    SConscript('build/src/matlab/SConscript')

if env['doxygen_docs'] or env['sphinx_docs']:
    SConscript('doc/SConscript')

if env["python_sdist"]:
    VariantDir("build/python_sdist", "interfaces/python_sdist", duplicate=1)
    SConscript("interfaces/python_sdist/SConscript", variant_dir="build/python_sdist")

# Sample programs (also used from test_problems/SConscript)
VariantDir('build/samples', 'samples', duplicate=0)
sampledir_excludes = ['\\.o$', '^~$', '\\.in', 'SConscript']
SConscript('build/samples/cxx/SConscript')

# Install C++ samples
install(env.RecursiveInstall, '$inst_sampledir/cxx',
        'samples/cxx', exclude=sampledir_excludes)

if env['f90_interface'] == 'y':
    SConscript('build/samples/f77/SConscript')
    SConscript('build/samples/f90/SConscript')

    # install F90 / F77 samples
    install(env.RecursiveInstall, '$inst_sampledir/f77',
            'samples/f77', sampledir_excludes)
    install(env.RecursiveInstall, '$inst_sampledir/f90',
            'samples/f90', sampledir_excludes)

### Meta-targets ###
build_samples = Alias('samples', sampleTargets)

def postBuildMessage(target, source, env):
    print("*******************************************************")
    print("Compilation completed successfully.\n")
    print("- To run the test suite, type 'scons test'.")
    print("- To list available tests, type 'scons test-help'.")
    if env['googletest'] == 'none':
        print("  WARNING: You set the 'googletest' to 'none' and all its tests will be skipped.")
    print("- To install, type 'scons install'.")
    if os.name == 'nt':
        print("- To create a Windows MSI installer, type 'scons msi'.")
    print("*******************************************************")

finish_build = env.Command('finish_build', [], postBuildMessage)
env.Depends(finish_build, buildTargets)
build_cantera = Alias('build', finish_build)

Default('build')

def postInstallMessage(target, source, env):
    # Only needed because Python 2 doesn't support textwrap.indent
    def indent(inp_str, indent):
        return '\n'.join([indent + spl for spl in inp_str.splitlines()])

    env_dict = env.Dictionary()
    locations = {
        "library files": "ct_libdir",
        "C++ headers": "ct_incroot",
        "samples": "ct_sampledir",
        "data files": "ct_datadir",
        "input file converters": "ct_pyscriptdir",
    }
    install_message = textwrap.dedent("""
        Cantera has been successfully installed.

        File locations:
        """
    ).splitlines()
    locations_message = "  {name:<28}{location}"
    for name, location in locations.items():
        install_message.append(locations_message.format(
            name=name, location=env_dict[location]
        ))

    if env["sphinx_docs"] or env["doxygen_docs"]:
        name = "HTML documentation"
        install_message.append(locations_message.format(
            name="HTML documentation", location=env_dict["inst_docdir"]
        ))

    if env["python_package"] == "full":
        env["python_example_loc"] = pjoin(env["python_module_loc"], "cantera", "examples")
        install_message.append(locations_message.format(
            name="Python package", location=env_dict["python_module_loc"]
        ))
        install_message.append(locations_message.format(
            name="Python examples", location=env_dict["python_example_loc"]
        ))

    if env["matlab_toolbox"] == "y":
        env["matlab_sample_loc"] = pjoin(env["ct_sampledir"], "matlab")
        env["matlab_ctpath_loc"] = pjoin(env["ct_matlab_dir"], "ctpath.m")
        install_message.append(locations_message.format(
            name="Matlab toolbox", location=env_dict["ct_matlab_dir"]
        ))
        install_message.append(locations_message.format(
            name="Matlab samples", location=env_dict["matlab_sample_loc"]
        ))
        install_message.append(textwrap.dedent("""
            An m-file to set the correct matlab path for Cantera is at:

              {matlab_ctpath_loc!s}
        """.format(**env_dict)))

    install_message.append("")

    logger.info(
        textwrap.indent("\n".join(install_message), 4*" "),
        print_level=False
    )

finish_install = env.Command("finish_install", [], postInstallMessage)
env.Depends(finish_install, installTargets)
install_cantera = Alias('install', finish_install)

### Uninstallation
def getParentDirs(path, top=True):
    head,tail = os.path.split(path)
    if head == os.path.abspath(env['prefix']):
        return [path]
    elif not tail:
        if head.endswith(os.sep):
            return []
        else:
            return [head]
    elif top:
        return getParentDirs(head, False)
    else:
        return getParentDirs(head, False) + [path]

# Files installed by SCons
allfiles = FindInstalledFiles()

# After removing files (which SCons keeps track of),
# remove any empty directories (which SCons doesn't track)
def removeDirectories(target, source, env):
    # Get all directories where files are installed
    alldirs = set()
    for f in allfiles:
        alldirs.update(getParentDirs(f.path))
    if env['layout'] == 'compact':
        alldirs.add(os.path.abspath(env['prefix']))
    # Sort in order of decreasing directory length so that empty subdirectories
    # will be removed before their parents are checked.
    alldirs = sorted(alldirs, key=lambda x: -len(x))

    # Don't remove directories that probably existed before installation,
    # even if they are empty
    keepDirs = ['local/share', 'local/lib', 'local/include', 'local/bin',
                'man/man1', 'dist-packages', 'site-packages']
    for d in alldirs:
        if any(d.endswith(k) for k in keepDirs):
            continue
        if os.path.isdir(d) and not os.listdir(d):
            os.rmdir(d)

uninstall = env.Command("uninstall", None, Delete(allfiles))
env.AddPostAction(uninstall, Action(removeDirectories))
if env["python_package"] == "full":
    env.AddPostAction(uninstall, Action("$python_cmd_esc -m pip uninstall -y Cantera"))
elif env["python_package"] == "minimal":
    env.AddPostAction(uninstall, Action("$python_cmd_esc -m pip uninstall -y Cantera_minimal"))

### Windows MSI Installer ###
if 'msi' in COMMAND_LINE_TARGETS:
    def build_wxs(target, source, env):
        import wxsgen
        wxs = wxsgen.WxsGenerator(env['stage_dir'],
                                  short_version=env['cantera_short_version'],
                                  full_version=env['cantera_pure_version'],
                                  x64=env['TARGET_ARCH']=='amd64',
                                  includeMatlab=env['matlab_toolbox']=='y')
        wxs.make_wxs(str(target[0]))

    wxs_target = env.Command('build/wix/cantera.wxs', [], build_wxs)
    env.AlwaysBuild(wxs_target)

    env.Append(WIXLIGHTFLAGS=['-ext', 'WixUIExtension'])
    msi_target = env.WiX('cantera.msi', ['build/wix/cantera.wxs'])
    env.Depends(wxs_target, installTargets)
    env.Depends(msi_target, wxs_target)
    build_msi = Alias('msi', msi_target)

### Tests ###
if any(target.startswith('test') for target in COMMAND_LINE_TARGETS):
    env['testNames'] = []
    env['test_results'] = env.Command('test_results', [], test_results.print_report)

    if env['python_package'] == 'none':
        # copy scripts from the full Cython module
        test_py_int = env.Command('#build/python_local/cantera/__init__.py',
                                  '#interfaces/python_minimal/cantera/__init__.py',
                                  Copy('$TARGET', '$SOURCE'))
        for script in ['ctml_writer', 'ck2cti', 'ck2yaml', 'ctml2yaml']:
            s = env.Command('#build/python_local/cantera/{}.py'.format(script),
                            '#interfaces/cython/cantera/{}.py'.format(script),
                            Copy('$TARGET', '$SOURCE'))
            env.Depends(test_py_int, s)

        env.Depends(env['test_results'], test_py_int)

        env['python_cmd'] = sys.executable
        env.PrependENVPath('PYTHONPATH', Dir('build/python_local').abspath)
    else:
        env.PrependENVPath('PYTHONPATH', Dir('build/python').abspath)

    env['ENV']['PYTHON_CMD'] = env.subst('$python_cmd')

    # Tests written using the gtest framework, the Python unittest module,
    # or the Matlab xunit package.
    VariantDir('build/test', 'test', duplicate=0)
    SConscript('build/test/SConscript')

    # Regression tests
    SConscript('test_problems/SConscript')

    if 'test-help' in COMMAND_LINE_TARGETS:
        print('\n*** Available tests ***\n')
        for name in env['testNames']:
            print('test-%s' % name)
        sys.exit(0)

    Alias('test', env['test_results'])

### Dump (debugging SCons)
if 'dump' in COMMAND_LINE_TARGETS:
    import pprint
    # Typical usage: 'scons build dump'
    print('os.environ:\n', pprint.pprint(dict(os.environ)))
    print('env.Dump():\n', env.Dump())
    sys.exit(0)