[BUG] Unprotected path for objects passed to windows linker

setuptools version

setuptools==73.0.1

Python version

Python 3.13

OS

Windows

Additional environment information

This happens on the conda-forge servers.

Description

An object file is passed to link.exe directly with its unix-like absolute path '/bld/gudhi_1725978620692/work/build/version/python/gudhi/off_utils.obj'. Since it starts with a '/', it is interpreted as an option and ignored.
(In the cl.exe command, the source filename is prefixed by /TpD: and the object by /Fo, so there is no problem there)
(We did not have this issue before because we always ended up with relative paths, which don't start with '/' and just work)

Expected behavior

It would be nice if the object was passed in a safe way. If there existed an option (tentatively called /Input here), it could pass /Input/path/to/file.obj instead of just /path/to/file.obj, but I didn't find it in the doc. More simply, it should be possible to sanitize the path (using functions from pathlib?) before using it, probably rewriting to \path\to\file.obj.

How to Reproduce

This is the build win_64_numpy2python3.13.____cp313 from
https://github.com/conda-forge/gudhi-feedstock/pull/67
(you can get a look at setup.py at https://github.com/GUDHI/gudhi-devel/blob/master/src/python/setup.py.in#L30)
I don't know how to reproduce their exact setup, maybe using an obsolute path somewhere is important.

Output

2024-09-10T14:47:13.1506361Z running build_ext
2024-09-10T14:47:13.1597057Z building 'gudhi.off_utils' extension
2024-09-10T14:47:13.1644903Z "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.29.30133\bin\HostX64\x64\cl.exe" /c /nologo /O2 /W3 /GL /DNDEBUG /MD -DNPY_NO_DEPRECATED_API=NPY_1_7_API_VERSION -I%PREFIX%\Lib\site-packages\numpy\_core\include -ID:/bld/gudhi_1725978620692/work/build/version/python/gudhi/ -ID:/bld/gudhi_1725978620692/_h_env/Library/include/eigen3 -ID:/bld/gudhi_1725978620692/_h_env/Library/include -ID:/bld/gudhi_1725978620692/_h_env/Library/include -ID:/bld/gudhi_1725978620692/work/build/version/ext/hera/include -ID:/bld/gudhi_1725978620692/_h_env/Library/include -ID:/bld/gudhi_1725978620692/_h_env/Library/include -ID:/bld/gudhi_1725978620692/work/build/version/include -ID:/bld/gudhi_1725978620692/work/build/version/python/include -I%PREFIX%\include -I%PREFIX%\Include "-IC:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.29.30133\include" "-IC:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\VS\include" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.22621.0\ucrt" "-IC:\Program Files (x86)\Windows Kits\10\\include\10.0.22621.0\\um" "-IC:\Program Files (x86)\Windows Kits\10\\include\10.0.22621.0\\shared" "-IC:\Program Files (x86)\Windows Kits\10\\include\10.0.22621.0\\winrt" "-IC:\Program Files (x86)\Windows Kits\10\\include\10.0.22621.0\\cppwinrt" "-IC:\Program Files (x86)\Windows Kits\NETFXSDK\4.8\include\um" -I%PREFIX%\Library\include -I%PREFIX%\Library\include /d1trimfile:%SRC_DIR% /EHsc /TpD:/bld/gudhi_1725978620692/work/build/version/python/gudhi/off_utils.cpp /Fo/bld/gudhi_1725978620692/work/build/version/python/gudhi/off_utils.obj -DBOOST_RESULT_OF_USE_DECLTYPE -DBOOST_ALL_NO_LIB -DBOOST_SYSTEM_NO_DEPRECATED /std:c++17 /fp:strict -DNOMINMAX -DCGAL_EIGEN3_ENABLED -DCGAL_HEADER_ONLY -DCGAL_USE_GMP -DCGAL_USE_MPFR
2024-09-10T14:47:13.1816038Z off_utils.cpp
2024-09-10T14:47:13.9596360Z creating %SRC_DIR%\build\version\build\python\build
2024-09-10T14:47:13.9617275Z creating %SRC_DIR%\build\version\build\python\build\lib.win-amd64-cpython-313
2024-09-10T14:47:14.0121940Z creating %SRC_DIR%\build\version\build\python\build\lib.win-amd64-cpython-313\gudhi
2024-09-10T14:47:14.1740722Z "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.29.30133\bin\HostX64\x64\link.exe" /nologo /INCREMENTAL:NO /LTCG /DLL /MANIFEST:EMBED,ID=2 /MANIFESTUAC:NO /LIBPATH:D:/bld/gudhi_1725978620692/_h_env/Library/lib /LIBPATH:D:/bld/gudhi_1725978620692/_h_env/Library/lib /LIBPATH:%PREFIX%\libs /LIBPATH:%PREFIX% /LIBPATH:%PREFIX%\PCbuild\amd64 "/LIBPATH:C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.29.30133\lib\x64" "/LIBPATH:C:\Program Files (x86)\Windows Kits\NETFXSDK\4.8\lib\um\x64" "/LIBPATH:C:\Program Files (x86)\Windows Kits\10\lib\10.0.22621.0\ucrt\x64" "/LIBPATH:C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64" /LIBPATH:%PREFIX%\Library\lib /LIBPATH:%PREFIX%\Library\lib gmp.lib mpfr.lib /EXPORT:PyInit_off_utils /bld/gudhi_1725978620692/work/build/version/python/gudhi/off_utils.obj /OUT:build\lib.win-amd64-cpython-313\gudhi\off_utils.cp313-win_amd64.pyd /IMPLIB:/bld/gudhi_1725978620692/work/build/version/python/gudhi\off_utils.cp313-win_amd64.lib
2024-09-10T14:47:14.2703556Z LINK : warning LNK4044: unrecognized option '/bld/gudhi_1725978620692/work/build/version/python/gudhi/off_utils.obj'; ignored
2024-09-10T14:47:14.2714614Z LINK : warning LNK4001: no object files specified; libraries used
2024-09-10T14:47:14.2742679Z LINK : warning LNK4068: /MACHINE not specified; defaulting to X64
2024-09-10T14:47:14.2798709Z LINK : error LNK2001: unresolved external symbol PyInit_off_utils
2024-09-10T14:47:14.2822359Z /bld/gudhi_1725978620692/work/build/version/python/gudhi\off_utils.cp313-win_amd64.lib : fatal error LNK1120: 1 unresolved externals

(full output at https://dev.azure.com/conda-forge/84710dde-1620-425b-80d0-4cf5baca359d/_apis/build/builds/1024741/logs/121)

Start at setuptools' Windows build_ext and MSVC linker invocation, using the reported setup.py scenario and command output as the reproduction. Trace how the absolute .obj path reaches link.exe and check existing Windows compiler tests before adding coverage. Done means an absolute object path is accepted by link.exe and the extension build completes without the reported linker warnings and unresolved symbol.