msys2 ucrt build error

[Marc Schafer]

I'm trying to install gevent in msys2 ucrt64 and I get the error below. Is there a workaround for it?

Best,

Marc

$ pip install gevent
Collecting gevent
  Using cached gevent-24.10.3.tar.gz (6.1 MB)
  Installing build dependencies ... error
  error: subprocess-exited-with-error

  × pip subprocess to install build dependencies did not run successfully.
  │ exit code: 1
  ╰─> [82 lines of output]
      Collecting setuptools>=40.8.0
        Using cached setuptools-75.3.0-py3-none-any.whl.metadata (6.9 kB)
      Collecting Cython>=3.0.11
        Using cached Cython-3.0.11-py2.py3-none-any.whl.metadata (3.2 kB)
      Collecting cffi>=1.17.1
        Using cached cffi-1.17.1.tar.gz (516 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'
      Collecting greenlet>=3.0.3
        Using cached greenlet-3.1.1-cp311-cp311-mingw_x86_64_ucrt.whl
      Collecting pycparser (from cffi>=1.17.1)
        Using cached pycparser-2.22-py3-none-any.whl.metadata (943 bytes)
      Using cached setuptools-75.3.0-py3-none-any.whl (1.3 MB)
      Using cached Cython-3.0.11-py2.py3-none-any.whl (1.2 MB)
      Using cached pycparser-2.22-py3-none-any.whl (117 kB)
      Building wheels for collected packages: cffi
        Building wheel for cffi (pyproject.toml): started
        Building wheel for cffi (pyproject.toml): finished with status 'error'
        error: subprocess-exited-with-error

        Building wheel for cffi (pyproject.toml) did not run successfully.
        exit code: 1

        [48 lines of output]
        _configtest.c:2:2: error: #error "not MSVC"
            2 | #error "not MSVC"
              |  ^~~~~
        Note: will not use '__thread' in the C code
        ***** The above error message can be safely ignored.

        running bdist_wheel
        running build
        running build_py
        creating build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/api.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/backend_ctypes.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/cffi_opcode.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/commontypes.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/cparser.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/error.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/ffiplatform.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/lock.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/model.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/pkgconfig.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/recompiler.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/setuptools_ext.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/vengine_cpy.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/vengine_gen.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/verifier.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/_imp_emulation.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/_shimmed_dist_utils.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/__init__.py -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/_cffi_include.h -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/parse_c_type.h -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/_embedding.h -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        copying src/cffi/_cffi_errors.h -> build/lib.mingw_x86_64_ucrt-cpython-311/cffi
        running build_ext
        building '_cffi_backend' extension
        creating build/temp.mingw_x86_64_ucrt-cpython-311/src/c
        gcc -DNDEBUG -g -fwrapv -O3 -Wall -march=nocona -msahf -mtune=generic -O2 -pipe -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector-strong -Wp,-D__USE_MINGW_ANSI_STDIO=1 -O3 -march=nocona -msahf -mtune=generic -O2 -pipe -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector-strong -Wp,-D__USE_MINGW_ANSI_STDIO=1 -O3 -DFFI_BUILDING=1 -ID:/msys64/ucrt64/include/python3.11 -c src/c/_cffi_backend.c -o build/temp.mingw_x86_64_ucrt-cpython-311/src/c/_cffi_backend.o
        src/c/_cffi_backend.c: In function 'b_do_dlopen':
        src/c/_cffi_backend.c:4568:40: error: passing argument 1 of 'PyUnicode_AsWideChar' from incompatible pointer type [-Wincompatible-pointer-types]
         4568 |             sz1 = PyUnicode_AsWideChar((PyUnicodeObject *)filename_unicode,
              |                                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
              |                                        |
              |                                        PyUnicodeObject *
        In file included from D:/msys64/ucrt64/include/python3.11/Python.h:51,
                         from src/c/_cffi_backend.c:2:
        D:/msys64/ucrt64/include/python3.11/unicodeobject.h:299:15: note: expected 'PyObject *' {aka 'struct _object *'} but argument is of type 'PyUnicodeObject *'
          299 |     PyObject *unicode,          /* Unicode object */
              |     ~~~~~~~~~~^~~~~~~
        error: command 'D:\\msys64\\ucrt64\\bin/gcc.EXE' 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 cffi
      Failed to build cffi
      ERROR: ERROR: Failed to build installable wheels for some pyproject.toml based projects (cffi)
      [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 build 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.

[Jason Madden]

The problem you're having is with the CFFI library dependency, not gevent. Perhaps check with that project.

CFFI is needed by gevent to use the libuv event loop, which is the event loop supported on Windows. 

Note that Windows is considered supported only for personal development, not for deployment.