Error message confusing if a tag is missing

[miohtama]

If a tag is missing from a Git repo and you try to install a package with version_info, the error message is little bit confusing. Expected result: Say a git tag is missing. Now you get:

[~/code/xxx/xxx-frontend]% pip install -e .
Obtaining file:///Users/mikko/code/xxx/xxx-frontend
    Complete output from command python setup.py egg_info:
    zip_safe flag not set; analyzing archive contents...

    Installed /Users/mikko/code/xxx/xxx-frontend/.eggs/setuptools_git_version-1.0.3-py3.5.egg
    fatal: No names found, cannot describe anything.
    Traceback (most recent call last):
      File "/Users/mikko/code/xxx/xxx-frontend/.eggs/setuptools_git_version-1.0.3-py3.5.egg/setuptools_git_version.py", line 10, in validate_version_format
      File "/usr/local/Cellar/python3/3.5.0/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 629, in check_output
        **kwargs).stdout
      File "/usr/local/Cellar/python3/3.5.0/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 711, in run
        output=stdout, stderr=stderr)
    subprocess.CalledProcessError: Command '['git', 'describe', '--tags', '--long', '--dirty']' returned non-zero exit status 128

    During handling of the above exception, another exception occurred:

    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/Users/mikko/code/xxx/xxx-frontend/setup.py", line 35, in <module>
        'setuptools >= 8.0',
      File "/usr/local/Cellar/python3/3.5.0/Frameworks/Python.framework/Versions/3.5/lib/python3.5/distutils/core.py", line 108, in setup
        _setup_distribution = dist = klass(attrs)
      File "/Users/mikko/code/xxx/venv/lib/python3.5/site-packages/setuptools/dist.py", line 272, in __init__
        _Distribution.__init__(self,attrs)
      File "/usr/local/Cellar/python3/3.5.0/Frameworks/Python.framework/Versions/3.5/lib/python3.5/distutils/dist.py", line 281, in __init__
        self.finalize_options()
      File "/Users/mikko/code/xxx/venv/lib/python3.5/site-packages/setuptools/dist.py", line 327, in finalize_options
        ep.load()(self, ep.name, value)
      File "/Users/mikko/code/xxx/xxx-frontend/.eggs/setuptools_git_version-1.0.3-py3.5.egg/setuptools_git_version.py", line 12, in validate_version_format
      File "/Users/mikko/code/xxx/venv/lib/python3.5/site-packages/pkg_resources/__init__.py", line 551, in get_distribution
        dist = get_provider(dist)
      File "/Users/mikko/code/xxx/venv/lib/python3.5/site-packages/pkg_resources/__init__.py", line 431, in get_provider
        return working_set.find(moduleOrReq) or require(str(moduleOrReq))[0]
      File "/Users/mikko/code/xxx/venv/lib/python3.5/site-packages/pkg_resources/__init__.py", line 952, in require
        needed = self.resolve(parse_requirements(requirements))
      File "/Users/mikko/code/xxx/venv/lib/python3.5/site-packages/pkg_resources/__init__.py", line 839, in resolve
        raise DistributionNotFound(req, requirers)
    pkg_resources.DistributionNotFound: The 'xxx-frontend' distribution was not found and is required by the application

    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /Users/mikko/code/xxx/xxx-frontend/
[venv][master]                                                                                                                  

[domenkozar]

We should also pass --always flag to git describe.

$ git describe --tags --long --dirty --always
266564d-dirty