Why the same code can be built and installed on Linux and macOS but not on Windows?

[sun1638650145]

I can use python setup.py install to install on Linux or macOS, but it will report an error on Windows. And this kind of error will only happen if you add a directory structure to the cpp source code, like the following pybind_example/backend/ops.cc (if it is such a structure pybind_example/ops.cc, you can successful compilation).

The following is the error message:

LINK : error LNK2001: unresolved external symbol PyInit_pybind_example/backend/ops
build\temp.win-amd64-3.7\Release\pybind_example/backend\ops.cp37-win_amd64.lib : fatal error LNK1120: 1 unresolved externals
error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio\\2019\\Enterprise\\VC\\Tools\\MSVC\\14.29.30133\\bin\\HostX86\\x64\\link.exe' failed with exit status 1120

I have been confused for three days, and the same error appears when using skbuild. I am a newbie in windows development.

[sun1638650145]

I have solved this problem. Because MSVC++ mistakenly regards pybind_example/backend/ops as a name instead of a path, so the link is wrong (on Unix-like, the symbol name during construction is probably like this pybind_example/backend/PyInit_ops). In setup.py, adding the following lines of code should solve the problem.

from unittest.mock import Mock
from pybind11.setup_helpers import build_ext

build_ext.get_export_symbols = Mock(return_value=None)

This is a similar question can also refer to. I put it here hoping to help people with the same problem😊.

[henryiii]

Should the paths be converted to Windows style? Those should get turned into "" somewhere, I'd think. Windows should see pybind_example\backend\ops as a path. Just a thought.

[sun1638650145]

@henryiii I tried the ideas you provided to solve the problem. So writing a function separately to modify the path format according to different OS is also a solution.

[henryiii]

function separately to modify the path format according to different OS

Well, Python has these. str(pathlib.Path()), etc.