Unable to run poetry under Python 2.7 (missing importlib_metadata)

[schinckel]

• I am on the latest Poetry version.
• I have searched the issues of this repo and believe that this is not a duplicate.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• OS version and name: macOS Catalina
• Poetry version: 0.12.17
• Link of a Gist with the contents of your pyproject.toml file: N/A

Issue

I am in the process of transitioning to Python 3. As such, I am moving from Pipenv to Poetry.

I have poetry installed using pipx, which is being used to run things like poetry lock, and that all works great.

However, in my tox environment, I use poetry as a "dep", and the poetry install before running my tests.

In Python 2.7, this throws an exception:

[ImportError]
No module named importlib_metadata  

When I run it using -vv, I can see that the problem is not to do with installing the dependencies as such, but actually when poetry tries to parse the lock file:

Exception trace:
 /Users/matt/Development/ROSS/datamine/.tox/py27/lib/python2.7/site-packages/cleo/application.py in run() at line 94
   status_code = self.do_run(input_, output_)
 /Users/matt/Development/ROSS/datamine/.tox/py27/lib/python2.7/site-packages/poetry/console/application.py in do_run() at line 88
   return super(Application, self).do_run(i, o)
 /Users/matt/Development/ROSS/datamine/.tox/py27/lib/python2.7/site-packages/cleo/application.py in do_run() at line 197
   status_code = command.run(input_, output_)
 /Users/matt/Development/ROSS/datamine/.tox/py27/lib/python2.7/site-packages/poetry/console/commands/command.py in run() at line 77
   return super(BaseCommand, self).run(i, o)
 /Users/matt/Development/ROSS/datamine/.tox/py27/lib/python2.7/site-packages/cleo/commands/base_command.py in run() at line 136
   self.initialize(input_, output_)
 /Users/matt/Development/ROSS/datamine/.tox/py27/lib/python2.7/site-packages/poetry/console/commands/env_command.py in initialize() at line 18
   current_env = Env.get(self.poetry.file.parent)
 /Users/matt/Development/ROSS/datamine/.tox/py27/lib/python2.7/site-packages/poetry/console/commands/command.py in poetry() at line 62
   return self.get_application().poetry
 /Users/matt/Development/ROSS/datamine/.tox/py27/lib/python2.7/site-packages/poetry/console/application.py in poetry() at line 55
   from poetry.poetry import Poetry
 /Users/matt/Development/ROSS/datamine/.tox/py27/lib/python2.7/site-packages/poetry/poetry.py in <module>() at line 11
   from .json import validate_object
 /Users/matt/Development/ROSS/datamine/.tox/py27/lib/python2.7/site-packages/poetry/json/__init__.py in <module>() at line 4
   import jsonschema
 /Users/matt/Development/ROSS/datamine/.tox/py27/lib/python2.7/site-packages/jsonschema/__init__.py in <module>() at line 33
   import importlib_metadata as metadata

It seems that poetry does not install importlib_metadata when being installed under Python 2.7: adding it as a secondary dependency to my tox environment fixes this.

[schinckel]

To be clear: I have a resolution - after some time I was able to see that I needed to have tox also install importlib_metadata, but this was non-obvious until running with poetry -vv, and I wonder if there is a way to have this install automatically as a dependency under Python 2.7?

[finswimmer]

Hello @schinckel,

this (or something similar?) was reported before in #1487 and should be fixed by #1586

So please try it out with the latest preview release.

I will close this issue for now. But please leave a comment, if you still have any problems. I can reopen it any time.

fin swimmer

[schinckel]

I’ll check it at work in a couple of hours, but I thought it was different because that was to do with 3.8: the change in that PR shouldn’t have any different behaviour on 2.7

[schinckel]

I think maybe something else (prior to this change) fixed the issue: it appears to be working (but I've come across other issues related to running poetry from within tox that I am partway through documenting).

I've started a clean run without the extra requirement in my tox.ini on my CI server: I should know shortly if it has worked.

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.