diff --git a/setup.cfg b/setup.cfg
index a5ef60265..cf28fc777 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -54,6 +54,8 @@ strict_optional = False
 filterwarnings =
     all
     ignore::DeprecationWarning:docutils.io
+    ignore::DeprecationWarning:pyximport.pyximport
+    ignore::PendingDeprecationWarning:sphinx.util.pycompat
 markers =
     sphinx
     apidoc
diff --git a/sphinx/util/pycompat.py b/sphinx/util/pycompat.py
index bcd90a718..7d22a792a 100644
--- a/sphinx/util/pycompat.py
+++ b/sphinx/util/pycompat.py
@@ -23,8 +23,15 @@ def convert_with_2to3(filepath: str) -> str:
     warnings.warn('convert_with_2to3() is deprecated',
                   RemovedInSphinx60Warning, stacklevel=2)
 
-    from lib2to3.refactor import RefactoringTool, get_fixers_from_package
-    from lib2to3.pgen2.parse import ParseError
+    try:
+        from lib2to3.refactor import RefactoringTool, get_fixers_from_package
+        from lib2to3.pgen2.parse import ParseError
+    except ImportError:
+        # python 3.9.0a6+ emits PendingDeprecationWarning for lib2to3.
+        # Additionally, removal of the module is still discussed at PEP-594.
+        # To support future python, this catches ImportError for lib2to3.
+        raise SyntaxError
+
     fixers = get_fixers_from_package('lib2to3.fixes')
     refactoring_tool = RefactoringTool(fixers)
     source = refactoring_tool._read_python_source(filepath)[0]
diff --git a/tests/roots/test-ext-autodoc/target/cython.pyx b/tests/roots/test-ext-autodoc/target/cython.pyx
index 31ef33c29..5d0329ae5 100644
--- a/tests/roots/test-ext-autodoc/target/cython.pyx
+++ b/tests/roots/test-ext-autodoc/target/cython.pyx
@@ -1,4 +1,5 @@
 # cython: binding=True
+# cython: language_level=3str
 
 def foo(x: int, *args, y: str, **kwargs):
     """Docstring."""
diff --git a/tests/test_ext_autosummary.py b/tests/test_ext_autosummary.py
index 63fafe860..f97840aa5 100644
--- a/tests/test_ext_autosummary.py
+++ b/tests/test_ext_autosummary.py
@@ -358,7 +358,7 @@ def test_autosummary_imported_members(app, status, warning):
 def test_generate_autosummary_docs_property(app):
     with patch('sphinx.ext.autosummary.generate.find_autosummary_in_files') as mock:
         mock.return_value = [AutosummaryEntry('target.methods.Base.prop', 'prop', None, False)]
-        generate_autosummary_docs([], output_dir=app.srcdir, builder=app.builder, app=app)
+        generate_autosummary_docs([], output_dir=app.srcdir, app=app)
 
     content = (app.srcdir / 'target.methods.Base.prop.rst').read_text()
     assert content == ("target.methods.Base.prop\n"
diff --git a/tests/test_markup.py b/tests/test_markup.py
index 1d5c81bfa..1b41dc69a 100644
--- a/tests/test_markup.py
+++ b/tests/test_markup.py
@@ -18,6 +18,7 @@ from docutils.transforms.universal import SmartQuotes
 from sphinx import addnodes
 from sphinx.builders.html.transforms import KeyboardTransform
 from sphinx.builders.latex import LaTeXBuilder
+from sphinx.builders.latex.theming import ThemeFactory
 from sphinx.roles import XRefRole
 from sphinx.testing.util import Struct, assert_node
 from sphinx.util import texescape
@@ -110,7 +111,8 @@ def verify_re_latex(app, parse):
         app.builder = LaTeXBuilder(app)
         app.builder.set_environment(app.env)
         app.builder.init()
-        latex_translator = ForgivingLaTeXTranslator(document, app.builder)
+        theme = app.builder.themes.get('manual')
+        latex_translator = ForgivingLaTeXTranslator(document, app.builder, theme)
         latex_translator.first_document = -1  # don't write \begin{document}
         document.walkabout(latex_translator)
         latex_translated = ''.join(latex_translator.body).strip()
diff --git a/tests/test_util_docstrings.py b/tests/test_util_docstrings.py
index 2f0901d06..a57e3f9b1 100644
--- a/tests/test_util_docstrings.py
+++ b/tests/test_util_docstrings.py
@@ -59,16 +59,6 @@ def test_prepare_docstring():
              "  Ut enim ad minim veniam, quis nostrud exercitation",
              "    ullamco laboris nisi ut aliquip ex ea commodo consequat.",
              ""])
-    assert (prepare_docstring(docstring, 5) ==
-            ["multiline docstring",
-             "",
-             "Lorem ipsum dolor sit amet, consectetur adipiscing elit,",
-             "sed do eiusmod tempor incididunt ut labore et dolore magna",
-             "aliqua::",
-             "",
-             "Ut enim ad minim veniam, quis nostrud exercitation",
-             "  ullamco laboris nisi ut aliquip ex ea commodo consequat.",
-             ""])
 
     docstring = """