python.library crumbles include directories

[naquad]

Xmake Version

2.9.1

Operating System Version and Architecture

Linux new-nq 6.8.7-zen1-1-zen #1 ZEN SMP PREEMPT_DYNAMIC Wed, 17 Apr 2024 15:20:00 +0000 x86_64 GNU/Linux

Describe Bug

python.library rules fail to build library.

Expected Behavior

Expected to build a library

Project Configuration

Took an example configuration from docs.

add_rules("mode.release", "mode.debug")
add_requires("pybind11")

target("example")
     add_rules("python.library")
     add_files("src/*.cpp")
     add_packages("pybind11")
     set_languages("c++11")

Additional Information and Error Logs

[ 50%]: cache compiling.release src/main.cpp
/usr/bin/gcc -c -m64 -fPIC -fvisibility=hidden -fvisibility-inlines-hidden -O3 -std=c++11 -isystem /usr/lib/pkgconfig/../../include -isystem /usr/include/python3.11 -DNDEBUG -o build/.objs/example/linux/x86_64/release/src/main.cpp.o src/main.cpp
error: In file included from /usr/include/c++/14.1.1/ext/string_conversions.h:43,
                 from /usr/include/c++/14.1.1/bits/basic_string.h:4154,
                 from /usr/include/c++/14.1.1/string:54,
                 from /usr/include/c++/14.1.1/stdexcept:39,
                 from /usr/lib/pkgconfig/../../include/pybind11/detail/../detail/common.h:320,
                 from /usr/lib/pkgconfig/../../include/pybind11/detail/../attr.h:13,
                 from /usr/lib/pkgconfig/../../include/pybind11/detail/class.h:12,
                 from /usr/lib/pkgconfig/../../include/pybind11/pybind11.h:13,
                 from src/main.cpp:1:
/usr/include/c++/14.1.1/cstdlib:79:15: fatal error: stdlib.h: No such file or directory
   79 | #include_next <stdlib.h>
      |               ^~~~~~~~~~
compilation terminated.

Happens on both
CLang 17.0.6
GCC 14.1.1

Surprisingly but xmake project -k cmake && cmake . && make is working.

[waruqi]

-isystem /usr/lib/pkgconfig/../../include -> /usr/include it will break gcc. gcc will not find stdlib.h

you can try add_requires("pybind11", {system = false}) to disable use pkg-config to find system libs.

[naquad]

Yes, this has helped, thank you 👍

However, the point was to build the bindings library only when there's a pybind11 in the system w/o downloading it. The fact that pkg-config is causing a build failure seems like a bug.

[waruqi]

Yes, this has helped, thank you 👍

However, the point was to build the bindings library only when there's a pybind11 in the system w/o downloading it. The fact that pkg-config is causing a build failure seems like a bug.

This is a known gcc issue, we can not set -isystem /usr/include to gcc.

However, we can't get pkg-config not to return the /usr/include path. This may also be an issue of pybind11's .pc file

• gcc seems broken msys2/MINGW-packages#10761

[naquad]

Is there some way to use -I instead of -isystem? Semantics is somewhat different, but it works then.

[waruqi]

add_requires("xxx", {external = false}) or set_policy("package.include_external_headers", false)

[naquad]

Perfect! Thank you. The first option is the way to go in my case.

Some further digging just for the reference. The output of the pkg-config is indeed questionable:

❯❯❯ pkg-config --cflags pybind11
-I/usr/lib/pkgconfig/../../include

I would rather expect Python's includes to be listed rather than just /usr/include but we have what we have. Given this and the conversion of the -I to -isystem by default, I think it is safe to say that the package itself (or its build) is a culprit, so it is a corner case and the issue can be closed.

Thank you again for the quick resolution.