PyYAML – error: subprocess-exited-with-error

I got this error when trying to install PyYAML

Collecting PyYAML==5.4.1 (from -r /xxx/src/requirements_2.txt (line 21))
  Using cached PyYAML-5.4.1.tar.gz (175 kB)
  Installing build dependencies ... done
  Getting requirements to build wheel ... error
  error: subprocess-exited-with-error
  
  × Getting requirements to build wheel did not run successfully.
  │ exit code: 1
  ╰─> [48 lines of output]
      running egg_info
      writing lib3/PyYAML.egg-info/PKG-INFO
      writing dependency_links to lib3/PyYAML.egg-info/dependency_links.txt
      writing top-level names to lib3/PyYAML.egg-info/top_level.txt
      Traceback (most recent call last):
        File "/xxx/env/lib/python3.9/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 353, in <module>
          main()
        File "/xxx/env/lib/python3.9/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 335, in main
          json_out['return_val'] = hook(**hook_input['kwargs'])
        File "/xxx/env/lib/python3.9/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 118, in get_requires_for_build_wheel
          return hook(config_settings)
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/build_meta.py", line 332, in get_requires_for_build_wheel
          return self._get_build_requires(config_settings, requirements=[])
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/build_meta.py", line 302, in _get_build_requires
          self.run_setup()
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/build_meta.py", line 318, in run_setup
          exec(code, locals())
        File "<string>", line 271, in <module>
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/__init__.py", line 117, in setup
          return distutils.core.setup(**attrs)
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/_distutils/core.py", line 184, in setup
          return run_commands(dist)
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/_distutils/core.py", line 200, in run_commands
          dist.run_commands()
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/_distutils/dist.py", line 954, in run_commands
          self.run_command(cmd)
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/dist.py", line 950, in run_command
          super().run_command(command)
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/_distutils/dist.py", line 973, in run_command
          cmd_obj.run()
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 311, in run
          self.find_sources()
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 319, in find_sources
          mm.run()
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 540, in run
          self.add_defaults()
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 578, in add_defaults
          sdist.add_defaults(self)
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/command/sdist.py", line 108, in add_defaults
          super().add_defaults()
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/_distutils/command/sdist.py", line 250, in add_defaults
          self._add_defaults_ext()
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/_distutils/command/sdist.py", line 335, in _add_defaults_ext
          self.filelist.extend(build_ext.get_source_files())
        File "<string>", line 201, in get_source_files
        File "/private/var/folders/c7/59xfc0ns6r9bz5h8lnhz0b140000gn/T/pip-build-env-k3l_7j20/overlay/lib/python3.9/site-packages/setuptools/_distutils/cmd.py", line 107, in __getattr__
          raise AttributeError(attr)
      AttributeError: cython_sources
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.
error: subprocess-exited-with-error

× Getting requirements to build wheel 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.

>Solution :

This seems to be a bug which is reported here. You can either downgrade PyYaml to 5.3.1 or try with this recommendation.

pip install "cython<3.0.0" && pip install --no-build-isolation pyyaml==5.4.1