Failure trying to pip install in Cygwin: "UserWarning: unprocessed git archival found (no export subst applied)"

Question

I'm trying to install some Python packages on Cygwin, on an X86_64 machine running Windows 10.

I've just updated my Cygwin distribution, and installed python. Now, using pip, some packages install fine, like argparse, but some just don't. The errors seem to be:

• UserWarning: git archive did not support describe output
• UserWarning: unprocessed git archival found (no export subst applied)

see a full trace below.

Why is this happening? And how can I fixed/circumvent this?

$ pip install ninja
Collecting ninja
  Using cached ninja-1.11.1.1.tar.gz (132 kB)
  Installing build dependencies ... done
  Getting requirements to build wheel ... done
  Preparing metadata (pyproject.toml) ... done
Building wheels for collected packages: ninja
  Building wheel for ninja (pyproject.toml) ... error
  error: subprocess-exited-with-error

  × Building wheel for ninja (pyproject.toml) did not run successfully.
  │ exit code: 1
  ╰─> [13 lines of output]
      /tmp/pip-build-env-8cad4e54/overlay/lib/python3.9/site-packages/setuptools_scm/git.py:312: UserWarning: git archive did not support describe output
        warnings.warn("git archive did not support describe output")
      /tmp/pip-build-env-8cad4e54/overlay/lib/python3.9/site-packages/setuptools_scm/git.py:331: UserWarning: unprocessed git archival found (no export subst applied)
        warnings.warn("unprocessed git archival found (no export subst applied)")
      Traceback (most recent call last):
        File "/tmp/pip-build-env-8cad4e54/overlay/lib/python3.9/site-packages/skbuild/setuptools_wrap.py", line 639, in setup
          cmkr = cmaker.CMaker(cmake_executable)
        File "/tmp/pip-build-env-8cad4e54/overlay/lib/python3.9/site-packages/skbuild/cmaker.py", line 145, in __init__
          self.cmake_version = get_cmake_version(self.cmake_executable)
        File "/tmp/pip-build-env-8cad4e54/overlay/lib/python3.9/site-packages/skbuild/cmaker.py", line 102, in get_cmake_version
          raise SKBuildError(msg) from err

      Problem with the CMake installation, aborting build. CMake executable is cmake
      [end of output]

  note: This error originates from a subprocess, and is likely not a problem with pip.
  ERROR: Failed building wheel for ninja
Failed to build ninja
ERROR: ERROR: Failed to build installable wheels for some pyproject.toml based projects (ninja)

More info about my setup:

• pip 24.2
• Python 3.9.16
• additional info will be provided upon request...

Related questions:

• I can't install any libraries, it gives me an error saying subprocess-exited-with-error

  where the solutio suggeted is

  setup the full python version

  $ sudo apt install python3-full

  ... but there's no such Cgwin package. I have installed some more Python packages I could think might br related, but to no avail.

Answer 1

You need to install the Cygwin packages cmake, make and ninja. cmake in itself won't suffice; and it's possible that just ninja would be enough. But the three of them together do the trick.

Thanks @Philippe for pointing out this avenue.