[Python] ImportError: undefined symbol: __powf_finite when importing pyflex extension built...

I’m building the SoftGym/PyFlex Python extension with CMake + pybind11 on Ubuntu. The build completes without errors, but when I try:

import pyflex


in the Python shell, I get:

ImportError: /…/softgym/PyFlex/bindings/build/pyflex.cpython-36m-x86_64-linux-gnu.so:
undefined symbol: __powf_finite


Environment

• Ubuntu 18.04 x86_64
• Python 3.6.13 (Anaconda)
• GCC 7.5.0
• CUDA 12.6
• CMake 3.10+
• pybind11 2.x
• SoftGym latest master

Here's an excerpt from my CMakeLists.txt:

find_package(CUDA REQUIRED)
find_package(pybind11 REQUIRED)

pybind11_add_module(pyflex ${SOURCES})

target_link_libraries(pyflex PRIVATE
EGL
${ROOT}/lib/linux64/NvFlexExtReleaseCUDA_x64.a
${ROOT}/lib/linux64/NvFlexReleaseCUDA_x64.a
${ROOT}/external/SDL2-2.0.4/lib/x64/libSDL2-2.0.so.0.4.0
${ROOT}/external/SDL2-2.0.4/lib/x64/libSDL2.a
${CUDA_LIBRARIES}
/usr/lib/x86_64-linux-gnu/libmvec.a # (attempted static link)
)


Build:

cd softgym/PyFlex/bindings
rm -rf build && mkdir build && cd build
cmake .. -DPYTHON_EXECUTABLE="$(which python)"
make -j8 VERBOSE=1 pyflex


What I’ve tried

• Linking -lm
• Wrapping m in -Wl,--whole-archive / --no-whole-archive
• Preloading libm.so.6 and libmvec.so.1 via LD_PRELOAD
• Statically linking both /usr/lib/.../libm.a and /usr/lib/.../libmvec.a

All yield the same undefined‐symbol error at import time.

Question What is the correct way to link or embed the standard math and vector‐math libraries so that __powf_finite is resolved inside the resulting .so? Are there additional linker flags or libraries I’m missing, or another approach to ensure Python can import pyflex without this error?

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