bpo-41282: Fix broken `make install` (GH-26329)
A previous commit broke a check in sysconfig when building cpython itself.
This caused builds of the standard library modules to search a wrong
location (the installed location rather than the source directory) for
header files with the net effect that a ``make install``
incorrectly caused all extension modules to be rebuilt again and
with incorrect include file paths.
When building Python, we need two distinct "include" directories:
- source .h files
- install target for .h files
Note that this doesn't matter except when building Python from source.
Historically:
- source .h files were in the distutils scheme under 'include'
- the install directory was in the distutils.command.install scheme
under 'headers'
GH-24549 merged these; sysconfig is now the single source of truth and
distutils is derived from it.
This commit introduces a "secret" scheme path, 'headers', which contains
the install target. It is only present when building Python.
The distutils code uses it if present, and falls back to 'include'.
Co-authored-by: Ned Deily <nad@python.org>
(cherry picked from commit 563bd5a4dcc6a26e47966cb66db64859902bce76)
Co-authored-by: Petr Viktorin <encukou@gmail.com>diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
index e8869af..730d33d 100644
--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -182,6 +182,18 @@ def is_python_build(check_home=False):
_PYTHON_BUILD = is_python_build(True)
+if _PYTHON_BUILD:
+ for scheme in ('posix_prefix', 'posix_home'):
+ # On POSIX-y platofrms, Python will:
+ # - Build from .h files in 'headers' (which is only added to the
+ # scheme when building CPython)
+ # - Install .h files to 'include'
+ scheme = _INSTALL_SCHEMES[scheme]
+ scheme['headers'] = scheme['include']
+ scheme['include'] = '{srcdir}/Include'
+ scheme['platinclude'] = '{projectbase}/.'
+
+
def _subst_vars(s, local_vars):
try:
return s.format(**local_vars)