Adjust library/header paths for cross-compilation When cross-compiling third-party extensions, the get_python_inc() or get_python_lib() can be called, to return the path to headers or libraries. However, they use the sys.prefix of the host Python, which returns incorrect paths when cross-compiling (paths pointing to host headers and libraries). In order to fix this, we introduce the _python_sysroot, _python_prefix and _python_exec_prefix variables, that allow to override these values, and get correct header/library paths when cross-compiling third-party Python modules. Signed-off-by: Thomas Petazzoni Index: b/Lib/distutils/sysconfig.py =================================================================== --- a/Lib/distutils/sysconfig.py +++ b/Lib/distutils/sysconfig.py @@ -16,10 +16,17 @@ from .errors import DistutilsPlatformError # These are needed in a couple of spots, so just compute them once. -PREFIX = os.path.normpath(sys.prefix) -EXEC_PREFIX = os.path.normpath(sys.exec_prefix) -BASE_PREFIX = os.path.normpath(sys.base_prefix) -BASE_EXEC_PREFIX = os.path.normpath(sys.base_exec_prefix) +if "_python_sysroot" in os.environ: + _sysroot=os.environ.get('_python_sysroot') + PREFIX = os.path.normpath(_sysroot + os.environ.get('_python_prefix')) + EXEC_PREFIX = os.path.normpath(_sysroot + os.environ.get('_python_exec_prefix')) + BASE_PREFIX = PREFIX + BASE_EXEC_PREFIX = EXEC_PREFIX +else: + PREFIX = os.path.normpath(sys.prefix) + EXEC_PREFIX = os.path.normpath(sys.exec_prefix) + BASE_PREFIX = os.path.normpath(sys.base_prefix) + BASE_EXEC_PREFIX = os.path.normpath(sys.base_exec_prefix) # Path to the base directory of the project. On Windows the binary may # live in project/PCBuild9. If we're dealing with an x64 Windows build, Index: b/Lib/distutils/command/build_ext.py =================================================================== --- a/Lib/distutils/command/build_ext.py +++ b/Lib/distutils/command/build_ext.py @@ -239,7 +239,10 @@ if (sysconfig.get_config_var('Py_ENABLE_SHARED')): if not sysconfig.python_build: # building third party extensions - self.library_dirs.append(sysconfig.get_config_var('LIBDIR')) + libdir = sysconfig.get_config_var('LIBDIR') + if "_python_sysroot" in os.environ: + libdir = os.environ.get("_python_sysroot") + libdir + self.library_dirs.append(libdir) else: # building python standard extensions self.library_dirs.append('.')