Breaking change in handling of some version constraints from `poetry-core` `1.0.0` to `1.1.0`

• 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: Mac OS X 11.6 (BigSur)
• Poetry version: 1.1.14 -> 1.2.0
• Link of a Gist with the contents of your pyproject.toml file:

Issue

I ran into an interesting bug (I’m not sure if it’s the root cause of some other issues, I had trouble finding a matching issue) where when poetry was using poetry-core==1.0.0 it was correctly resolving the version constraint of a somewhat non-standard semver version, but once poetry started using version poetry-core==1.1.0, it’s no longer correctly resolving the same version constraint, resulting in dependency resolution issues because the resolved constraint is never satisfiable.

For more context, in my current project, I’m pulling in a library:

opentelemetry-instrumentation-fastapi = "^0.32b0"

Where the next available version is 0.33b0.

In a version of poetry that uses poetry-core==1.0.0 , it correctly resolves this constraint:

# pip install poetry-core==1.0.0
# python <<EOF
from poetry.core.semver import parse_constraint
print(parse_constraint("^0.32b0"))
EOF

This will output >=0.32b0,<0.33, which is what ultimately ends up in setup.py when publishing with poetry.

Now, using poetry-core==1.1.0:

# pip install poetry-core==1.1.0
# python <<EOF
from poetry.core.semver.version import Version 
print(Version.parse("0.32b0").next_breaking())
EOF

This will output 0.32, which ultimately will get translated to a constraint that’s unsolvable >=0.32b0,<0.32 in setup.py:

install_requires = \
['fastapi-versioning>=0.10.0,<0.11.0',
 'fastapi>=0.79.0,<0.80.0',
 'gprof2dot>=2022.7.29,<2023.0.0',
 'opentelemetry-instrumentation-fastapi>=0.32b0,<0.32',  # <-- here
 'opentelemetry-instrumentation-logging>=0.32b0,<0.32',  # <-- and here
 'requests>=2.27.1,<3.0.0',
 'splunk-opentelemetry[all]>=1.7.0,<2.0.0',
 'starlette-exporter>=0.14.0,<0.15.0',
 'uvicorn[standard]>=0.18.2,<0.19.0']

Ultimately, after upgrading to poetry version 1.2.0 and publishing my package, it could no longer be installed because this version constraint could no longer be satisfied, resulting in a breaking change. I’ve worked around this for now by specifying an explicit version constraint, but, wanted to see if this is something that anyone else has noticed, if this is a “won’t fix” type situation, since the version is somewhat non-standard, etc.

[dimbleby]

though fwiw >=0.32b0,<0.32 is not unsolvable: it allows 0.32b0 (and 0.32b1, etc)

[dimbleby]

yep, I think we’re all on the same page now.

If you can get https://github.com/python-poetry/poetry-core/pull/475 over the line everything should be good