Unfriendly error when the version can't be determined #445
Description
Given this setup:
$ ls
changes towncrier.toml
$ cat towncrier.toml
[tool.towncrier]
directory = "changes"running towncrier build yields this error message:
Loading template...
Finding news fragments...
Rendering news fragments...
Traceback (most recent call last):
File "/home/dpb/.local/bin/towncrier", line 8, in <module>
sys.exit(cli())
File "/home/dpb/.local/pipx/venvs/towncrier/lib/python3.10/site-packages/click/core.py", line 1130, in __call__
return self.main(*args, **kwargs)
File "/home/dpb/.local/pipx/venvs/towncrier/lib/python3.10/site-packages/click/core.py", line 1055, in main
rv = self.invoke(ctx)
File "/home/dpb/.local/pipx/venvs/towncrier/lib/python3.10/site-packages/click/core.py", line 1657, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/home/dpb/.local/pipx/venvs/towncrier/lib/python3.10/site-packages/click/core.py", line 1404, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/home/dpb/.local/pipx/venvs/towncrier/lib/python3.10/site-packages/click/core.py", line 760, in invoke
return __callback(*args, **kwargs)
File "/home/dpb/.local/pipx/venvs/towncrier/lib/python3.10/site-packages/towncrier/build.py", line 89, in _main
return __main(
File "/home/dpb/.local/pipx/venvs/towncrier/lib/python3.10/site-packages/towncrier/build.py", line 147, in __main
project_version = get_version(
File "/home/dpb/.local/pipx/venvs/towncrier/lib/python3.10/site-packages/towncrier/_project.py", line 40, in get_version
module = _get_package(package_dir, package)
File "/home/dpb/.local/pipx/venvs/towncrier/lib/python3.10/site-packages/towncrier/_project.py", line 19, in _get_package
module = import_module(package)
File "/usr/lib/python3.10/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1047, in _gcd_import
File "<frozen importlib._bootstrap>", line 981, in _sanity_check
ValueError: Empty module name
This in no way describes the actual problem, which is that towncrier couldn't determine the project version. It would be nice if it could display a friendlier message, e.g. "Unable to determine the project version. Use the --version option."