Maximum recursion depth exceeded

• 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: OS X 10.14.5
• Poetry version: 0.12.17

[tool.black]
skip-string-normalization = true

[tool.poetry]
name = "kompost"
version = "0.1.0"
description = ""
authors = ["Software Team <[e-mail]>"]

[tool.poetry.dependencies]
celery = "*"
flask-celeryext = "*"

[build-system]
requires = ["poetry"]
build-backend = "poetry.masonry.api"

Issue

poetry install --dry-run                                                                    5.7s  Fri 19 Jul 14:57:40 2019
Updating dependencies
Resolving dependencies... (24.2s)

[RecursionError]
maximum recursion depth exceeded

install [--no-dev] [--dry-run] [-E|--extras EXTRAS] [--develop DEVELOP]

poetry debug:resolve -vvv
Resolving dependencies...
   1: fact: kompost is 0.1.0
   1: derived: kompost
   1: fact: kompost depends on celery (*)
   1: fact: kompost depends on flask-celeryext (*)
   1: selecting kompost (0.1.0)
   1: derived: flask-celeryext (*)
   1: derived: celery (*)
PyPI: 7 packages found for flask-celeryext *
PyPI: 132 packages found for celery *
   0: Duplicate dependencies for celery
   0: Different requirements found for celery (>=3.1) and celery (>=4.3).
   1: Version solving took 0.096 seconds.
   1: Tried 1 solutions.
   0: Retrying dependency resolution for Python (>=3.7,<3.8).
   1: fact: kompost is 0.1.0
   1: derived: kompost
   1: fact: kompost depends on celery (*)
   1: fact: kompost depends on flask-celeryext (*)
   1: selecting kompost (0.1.0)
   1: derived: flask-celeryext (*)
   1: derived: celery (*)
   0: Duplicate dependencies for celery
   0: Different requirements found for celery (>=3.1) and celery (>=4.3).

[s0undt3ch]

I think this problem is too impactful to be quiet for so long(while work arounds might be useful, they don’t solve the issue) The reason why I tried poetry was because of its dependency resolution(in particular it’s support for multiple OS’es resolution). I know this is open source and don’t take this as a demand for a quick fix or anything like that, but could we have some kind of update on the issue? Is this something that someone with minimal knowledge of the dependency resolution algorithm could help out?

[hernrup-modelon]

I second this issue. It makes it impassible to select different versions depending on operating system. This is critical for packages where specially compiled versions are needed on windows… because of windows.