setuptools install PYTHONPATH circumvention.

python/setup.py

@@ -10,6 +10,24 @@ import os
 import subprocess
 import argparse
 
+
+parser = argparse.ArgumentParser()
+parser.add_argument("build")
+parser.add_argument("build_ext")
+parser.add_argument("--build-lib")
+parser.add_argument("--prefix")
+parser.add_argument("--library-dirs")
+parser.add_argument("--include-dirs")
+parser.add_argument("--dry-run", action='store_true')
+args = parser.parse_args()
+
+#Circumnventing setuptools' PYTHONPATH check.
+#This is necessary during install
+if args.prefix:
+   python_version = 'python' + str(sys.version_info.major) + '.' + str(sys.version_info.minor)
+   pkg_path_root = os.path.join(args.prefix, 'lib', python_version, 'site-packages')
+   os.environ['PYTHONPATH'] += ':' + pkg_path_root
+
 setupdir = os.path.dirname(__file__)
 if setupdir != '':
   os.chdir( setupdir )