AttributeError while installing Pydantic with Python 3.8

• 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: Ubuntu 20.04.3 LTS

• Poetry version: 1.1.10

• Link of a Gist with the contents of your pyproject.toml file:

I tried this both with Python 3.7.12 and Python 3.8.10 and Poetry is able to install Pydantic when my system python is 3.7.12 (and the installer script install-poetry.py is also run with Python3.7, I haven’t tried installing poetry with Python 3.8 but using a dev environment with 3.7). However with Python 3.8.10, while installing Pydantic, this is the AssertionError that is raised. Output in debug mode:

PyPI: 78 packages found for pydantic *
Using version ^1.8.2 for pydantic

Updating dependencies
Resolving dependencies...
   1: fact: poetry-demo is 0.1.0
   1: derived: poetry-demo
   1: fact: poetry-demo depends on pydantic (^1.8.2)
   1: fact: poetry-demo depends on pytest (^5.2)
   1: fact: poetry-demo depends on pytest (^5.2)
   1: selecting poetry-demo (0.1.0)
   1: derived: pytest (>=5.2,<6.0)
   1: derived: pydantic (>=1.8.2,<2.0.0)
   1: fact: pytest (5.4.3) depends on py (>=1.5.0)
   1: fact: pytest (5.4.3) depends on packaging (*)
   1: fact: pytest (5.4.3) depends on attrs (>=17.4.0)
   1: fact: pytest (5.4.3) depends on more-itertools (>=4.0.0)
   1: fact: pytest (5.4.3) depends on pluggy (>=0.12,<1.0)
   1: fact: pytest (5.4.3) depends on wcwidth (*)
   1: fact: pytest (5.4.3) depends on atomicwrites (>=1.0)
   1: fact: pytest (5.4.3) depends on colorama (*)
   1: selecting pytest (5.4.3)
   1: derived: colorama
   1: derived: atomicwrites (>=1.0)
   1: derived: wcwidth
   1: derived: pluggy (>=0.12,<1.0)
   1: derived: more-itertools (>=4.0.0)
   1: derived: attrs (>=17.4.0)
   1: derived: packaging
   1: derived: py (>=1.5.0)
PyPI: 1 packages found for pydantic >=1.8.2,<2.0.0
   1: fact: pydantic (1.8.2) depends on typing-extensions (>=3.7.4.3)
   1: selecting pydantic (1.8.2)
   1: derived: typing-extensions (>=3.7.4.3)
   1: selecting wcwidth (0.2.5)
   1: selecting pluggy (0.13.1)
   1: selecting more-itertools (8.10.0)
   1: selecting attrs (21.2.0)
   1: fact: packaging (21.0) depends on pyparsing (>=2.0.2)
   1: selecting packaging (21.0)
   1: derived: pyparsing (>=2.0.2)
   1: selecting py (1.10.0)
   1: selecting typing-extensions (3.10.0.2)
   1: selecting pyparsing (2.4.7)
   1: selecting colorama (0.4.4)
   1: selecting atomicwrites (1.4.0)
   1: Version solving took 0.032 seconds.
   1: Tried 1 solutions.

Finding the necessary packages for the current system

Package operations: 1 install, 0 updates, 0 removals, 11 skipped

  • Removing atomicwrites (1.4.0): Pending...
  • Removing atomicwrites (1.4.0): Skipped for the following reason: Not currently installed
  • Removing colorama (0.4.4): Pending...
  • Removing colorama (0.4.4): Skipped for the following reason: Not currently installed
  • Installing pyparsing (2.4.7): Pending...
  • Installing pyparsing (2.4.7): Skipped for the following reason: Already installed
  • Installing attrs (21.2.0): Pending...
  • Installing attrs (21.2.0): Skipped for the following reason: Already installed
  • Installing more-itertools (8.10.0): Pending...
  • Installing more-itertools (8.10.0): Skipped for the following reason: Already installed
  • Installing packaging (21.0): Pending...
  • Installing packaging (21.0): Skipped for the following reason: Already installed
  • Installing pluggy (0.13.1): Pending...
  • Installing pluggy (0.13.1): Skipped for the following reason: Already installed
  • Installing py (1.10.0): Pending...
  • Installing py (1.10.0): Skipped for the following reason: Already installed
  • Installing typing-extensions (3.10.0.2): Pending...
  • Installing typing-extensions (3.10.0.2): Skipped for the following reason: Already installed
  • Installing wcwidth (0.2.5): Pending...
  • Installing wcwidth (0.2.5): Skipped for the following reason: Already installed
  • Installing pydantic (1.8.2): Pending...
  • Installing pydantic (1.8.2): Failed

  AttributeError

  'Link' object has no attribute 'name'

  at ~/.local/share/pypoetry/venv/lib/python3.8/site-packages/poetry/installation/executor.py:632 in _download_link
      628│                 raise RuntimeError(
      629│                     "Invalid hashes ({}) for {} using archive {}. Expected one of {}.".format(
      630│                         ", ".join(sorted(archive_hashes)),
      631│                         package,
    → 632│                         archive.name,
      633│                         ", ".join(sorted(hashes)),
      634│                     )
      635│                 )
      636│ 

  • Installing pytest (5.4.3): Pending...
  • Installing pytest (5.4.3): Skipped for the following reason: Already installed

Failed to add packages, reverting the pyproject.toml file to its original content.

[miohtama]

I started a new project and encountered this error, so it cannot be related to the old lock file or similar. I suggest it might be related to corrupted caches, or something in the cache. I managed to workaround with the following.

To downgrade Poetry to 1.1.8:

wget -S https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py 
python get-poetry.py --version 1.1.8  

Make sure your cache is nuked.

poetry cache clear . --all
# macOS
rm -rf ~/Library/Caches/pypoetry/artifacts  

Then this worked again

poetry add ipdb

[wojdatto]

I had the same issue ('Link' object has no attribute 'name') during poetry install of a different set of packages. Downgrading to poetry 1.1.8 and poetry-core 1.0.4 (I think the latter makes the difference here) solved it. I’m not sure about the root cause, though.

My clue was taken from the author of #4528.