Poetry: installing scrapy=2.3.0 using poetry fails with [RecursionError]

Created on 29 Aug 2020 · 3Comments · Source: python-poetry/poetry

[X ] I am on the latest Poetry version.
[ X] I have searched the issues of this repo and believe that this is not a duplicate.
[ X] 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: 1.0.10
Link of a Gist with the contents of your pyproject.toml file: n.a.

Issue

mkdir test
cd test
poetry init
poetry add scrapy=2.3.0 #scrapy=2.2.0 works!
poetry lock

fails with:

Updating dependencies
Resolving dependencies... (6.2s)

[RecursionError]
maximum recursion depth exceeded while calling a Python object

debugging with -vvv gives:

   0: Different requirements found for lxml (>=3.5.0) and lxml (>=4.0.0).
   1: Version solving took 0.017 seconds.
   1: Tried 1 solutions.
   0: Retrying dependency resolution for Python (>=3.8,<4.0).
   1: fact: test is 0.1.0
   1: derived: test
   1: fact: test depends on scrapy (^2.3.0)
   1: selecting test (0.1.0)
   1: derived: scrapy (^2.3.0)
   0: Duplicate dependencies for lxml

This problem might be related to the specific way scrapy sets up their dependencies:

https://github.com/scrapy/scrapy/blob/be655b855da3f5643b004e9f2d5b9161266c17f4/setup.py#L40

I also opened a scrapy-issue on this:

https://github.com/scrapy/scrapy/issues/4767

Bug

Source