Compilation error while compiling cppyy

[Vipul-Cariappa]

I am following the compilation from the README file. I get the following error message while compiling cppyy package.

❯ python -m pip install --upgrade . --no-deps
Processing /home/vipul/Workspace/c/cppyy-compiler-research
  Installing build dependencies ... done
  Getting requirements to build wheel ... done
  Installing backend dependencies ... error
  error: subprocess-exited-with-error
  
  × pip subprocess to install backend dependencies did not run successfully.
  │ exit code: 1
  ╰─> [49 lines of output]
      Collecting cppyy-cling==6.28.0
        Using cached cppyy_cling-6.28.0-py2.py3-none-manylinux2014_x86_64.whl.metadata (2.0 kB)
      Collecting cppyy-backend==1.14.11
        Using cached cppyy-backend-1.14.11.tar.gz (34 kB)
        Installing build dependencies: started
        Installing build dependencies: finished with status 'done'
        Getting requirements to build wheel: started
        Getting requirements to build wheel: finished with status 'done'
        Preparing metadata (pyproject.toml): started
        Preparing metadata (pyproject.toml): finished with status 'done'
      Using cached cppyy_cling-6.28.0-py2.py3-none-manylinux2014_x86_64.whl (42.2 MB)
      Building wheels for collected packages: cppyy-backend
        Building wheel for cppyy-backend (pyproject.toml): started
        Building wheel for cppyy-backend (pyproject.toml): finished with status 'error'
        error: subprocess-exited-with-error
      
        × Building wheel for cppyy-backend (pyproject.toml) did not run successfully.
        │ exit code: 1
        ╰─> [24 lines of output]
            running bdist_wheel
            running build
            running build_ext
            checking for build/temp.linux-x86_64-cpython-312
            creating build/temp.linux-x86_64-cpython-312
            creating build/temp.linux-x86_64-cpython-312/src
            gcc -pthread -B /home/vipul/micromamba/envs/compiler-research/compiler_compat -fno-strict-overflow -DNDEBUG -O2 -Wall -fPIC -O2 -isystem /home/vipul/micromamba/envs/compiler-research/include -fPIC -O2 -isystem /home/vipul/micromamba/envs/compiler-research/include -fPIC -I/tmp/pip-build-env-i51to3pf/overlay/lib/python3.12/site-packages/cppyy_backend/include -I/home/vipul/micromamba/envs/compiler-research/include/python3.12 -c src/clingwrapper.cxx -o build/temp.linux-x86_64-cpython-312/src/clingwrapper.o -O2 -pthread -std=c++1z -m64
            In file included from /tmp/pip-build-env-i51to3pf/overlay/lib/python3.12/site-packages/cppyy_backend/include/Rtypes.h:30,
                             from src/callcontext.h:11,
                             from src/clingwrapper.cxx:11:
            /usr/include/string.h:506:15: error: declaration of ‘size_t strlcpy(char*, const char*, size_t) noexcept’ has a different exception specifier
              506 | extern size_t strlcpy (char *__restrict __dest,
                  |               ^~~~~~~
            In file included from /tmp/pip-build-env-i51to3pf/overlay/lib/python3.12/site-packages/cppyy_backend/include/Rtypes.h:26:
            /tmp/pip-build-env-i51to3pf/overlay/lib/python3.12/site-packages/cppyy_backend/include/strlcpy.h:26:8: note: from previous declaration ‘size_t strlcpy(char*, const char*, size_t)’
               26 | size_t strlcpy(char *dst, const char *src, size_t siz);
                  |        ^~~~~~~
            /usr/include/string.h:512:15: error: declaration of ‘size_t strlcat(char*, const char*, size_t) noexcept’ has a different exception specifier
              512 | extern size_t strlcat (char *__restrict __dest,
                  |               ^~~~~~~
            /tmp/pip-build-env-i51to3pf/overlay/lib/python3.12/site-packages/cppyy_backend/include/strlcpy.h:27:8: note: from previous declaration ‘size_t strlcat(char*, const char*, size_t)’
               27 | size_t strlcat(char *dst, const char *src, size_t siz);
                  |        ^~~~~~~
            error: command '/usr/bin/gcc' failed with exit code 1
            [end of output]
      
        note: This error originates from a subprocess, and is likely not a problem with pip.
        ERROR: Failed building wheel for cppyy-backend
      Failed to build cppyy-backend
      ERROR: Could not build wheels for cppyy-backend, which is required to install pyproject.toml-based projects
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.
error: subprocess-exited-with-error

× pip subprocess to install backend dependencies did not run successfully.
│ exit code: 1
╰─> See above for output.

note: This error originates from a subprocess, and is likely not a problem with pip.

---

Googleing around, I found a similar issue at root-project/root#13156.

I fixed it by commenting out the declarations of strlcpy and strlcat functions from /usr/include/string.h file. It did compile after that. But this should not be recommended.

[aaronj0]

It uses the pip package cppyy-cling instead of the libcppyy-backend that you build.
Should be solved by doing:

python -m pip install --upgrade . --no-deps --no-build-isolation

Commenting out the string function headers is not the right solution since you are still using the cppyy-cling backend

[Vipul-Cariappa]

I faced this issue on Fedora. It worked fine on Ubuntu.

[vgvassilev]

Is that still a problem? If not maybe close it?