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

• OS version and name: Ubuntu 20.04
• Poetry version: 1.1.0
• Link of a Gist with the contents of your pyproject.toml file: https://gist.github.com/konstin/8d8c412fdd1ed76e2c42cea8e444f891

Issue

After updating to poetry 1.1.0, poetry fails with an AssertionError. You can reproduce this by adding the pyproject.toml linked above to an empty directory and running poetry install.

Logs

After 1: Version solving took 0.600 seconds. and 1: Tried 1 solutions., I get:

  AssertionError

  

  at ~/.poetry/lib/poetry/mixology/incompatibility.py:60 in __init__
       56│                     # intersection, they're mutually exclusive, making this incompatibility
       57│                     # irrelevant, since we already know that mutually exclusive version
       58│                     # ranges are incompatible. We should never derive an irrelevant
       59│                     # incompatibility.
    →  60│                     assert by_ref[ref] is not None
       61│                 else:
       62│                     by_ref[ref] = term
       63│ 
       64│             new_terms = []