Poetry 1.2.0a2 issue adding packages with major version 0 (version 0.Y.Z) using only ^0

[ESKYoung]

• I am on the latest Poetry version. Actually on preview version 1.2.0a2
• 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: macOS Monterey version 12.2.1
• Poetry version: 1.2.0a2
• Link of a Gist with the contents of your pyproject.toml file: Gist Link

Issue

Poetry 1.2.0a2 cannot find matching package versions for major version 0, where the caret is supplied as ^0 only. This works on Poetry 1.1, and is also a dependency specification example in the master documentation.

For example, using scikit-learn (the error occurs when adding other packages with the ^0 condition):

poetry add scikit-learn@^0  # fails
poetry add scikit-learn@^0.24  # works — installs the latest 0.24.Z version (0.24.2) as expected
poetry add "scikit-learn<1"  # works — installs the latest 0.Y.Z version (0.24.2) as expected

Running poetry add scikit-learn@^0 -vvv shows the following:

Using virtualenv: /Users/{USER_NAME}/Library/Caches/pypoetry/virtualenvs/poetry-bug-k1OA12gR-py3.9
PyPI: No release information found for scikit-learn-0.14a1, skipping
PyPI: 0 packages found for scikit-learn >=0,<0.1

  Stack trace:

  9  ~/.poetry/venv/lib/python3.9/site-packages/cleo/application.py:330 in run
      328│ 
      329│             try:
    → 330│                 exit_code = self._run(io)
      331│             except Exception as e:
      332│                 if not self._catch_exceptions:

  8  ~/.poetry/venv/lib/python3.9/site-packages/poetry/console/application.py:180 in _run
      178│         self._load_plugins(io)
      179│ 
    → 180│         return super()._run(io)
      181│ 
      182│     def _configure_io(self, io: IO) -> None:

  7  ~/.poetry/venv/lib/python3.9/site-packages/cleo/application.py:425 in _run
      423│                 io.set_input(ArgvInput(argv))
      424│ 
    → 425│         exit_code = self._run_command(command, io)
      426│         self._running_command = None
      427│ 

  6  ~/.poetry/venv/lib/python3.9/site-packages/cleo/application.py:467 in _run_command
      465│ 
      466│         if error is not None:
    → 467│             raise error
      468│ 
      469│         return event.exit_code

  5  ~/.poetry/venv/lib/python3.9/site-packages/cleo/application.py:451 in _run_command
      449│ 
      450│             if event.command_should_run():
    → 451│                 exit_code = command.run(io)
      452│             else:
      453│                 exit_code = ConsoleCommandEvent.RETURN_CODE_DISABLED

  4  ~/.poetry/venv/lib/python3.9/site-packages/cleo/commands/base_command.py:118 in run
      116│         io.input.validate()
      117│ 
    → 118│         status_code = self.execute(io)
      119│ 
      120│         if status_code is None:

  3  ~/.poetry/venv/lib/python3.9/site-packages/cleo/commands/command.py:85 in execute
       83│ 
       84│         try:
    →  85│             return self.handle()
       86│         except KeyboardInterrupt:
       87│             return 1

  2  ~/.poetry/venv/lib/python3.9/site-packages/poetry/console/commands/add.py:139 in handle
      137│             return 0
      138│ 
    → 139│         requirements = self._determine_requirements(
      140│             packages,
      141│             allow_prereleases=self.option("allow-prereleases"),

  1  ~/.poetry/venv/lib/python3.9/site-packages/poetry/console/commands/init.py:352 in _determine_requirements
      350│                 # check that the specified version/constraint exists
      351│                 # before we proceed
    → 352│                 name, _ = self._find_best_version_for_package(
      353│                     requirement["name"],
      354│                     requirement["version"],

  ValueError

  Could not find a matching version of package scikit-learn

  at ~/.poetry/venv/lib/python3.9/site-packages/poetry/console/commands/init.py:381 in _find_best_version_for_package
      377│         )
      378│ 
      379│         if not package:
      380│             # TODO: find similar
    → 381│             raise ValueError(
      382│                 "Could not find a matching version of package {}".format(name)
      383│             )
      384│ 
      385│         return package.pretty_name, selector.find_recommended_require_version(package)

If scikit-learn = "^0" is added manually to the pyproject.toml, poetry install -vvv shows:

Using virtualenv: /Users/{USER_NAME}/Library/Caches/pypoetry/virtualenvs/poetry-bug-k1OA12gR-py3.9
Updating dependencies
Resolving dependencies...
   1: fact: poetry-bug is 0.1.0
   1: derived: poetry-bug
   1: fact: poetry-bug depends on scikit-learn (^0)
   1: selecting poetry-bug (0.1.0)
   1: derived: scikit-learn (>=0,<0.1)
   1: fact: no versions of scikit-learn match >=0,<0.1
   1: conflict: no versions of scikit-learn match >=0,<0.1
   1: ! scikit-learn (>=0,<0.1) is satisfied by scikit-learn (>=0,<0.1)
   1: ! which is caused by "poetry-bug depends on scikit-learn (^0)"
   1: ! thus: version solving failed
   1: Version solving took 0.040 seconds.
   1: Tried 1 solutions.

  Stack trace:

  4  ~/.poetry/venv/lib/python3.9/site-packages/poetry/puzzle/solver.py:138 in _solve
      136│ 
      137│         try:
    → 138│             result = resolve_version(
      139│                 self._package, self._provider, locked=locked, use_latest=use_latest
      140│             )

  3  ~/.poetry/venv/lib/python3.9/site-packages/poetry/mixology/__init__.py:24 in resolve_version
       22│     solver = VersionSolver(root, provider, locked=locked, use_latest=use_latest)
       23│ 
    →  24│     return solver.solve()
       25│ 

  2  ~/.poetry/venv/lib/python3.9/site-packages/poetry/mixology/version_solver.py:81 in solve
       79│             next = self._root.name
       80│             while next is not None:
    →  81│                 self._propagate(next)
       82│                 next = self._choose_package_version()
       83│ 

  1  ~/.poetry/venv/lib/python3.9/site-packages/poetry/mixology/version_solver.py:121 in _propagate
      119│                     # where that incompatibility will allow us to derive new assignments
      120│                     # that avoid the conflict.
    → 121│                     root_cause = self._resolve_conflict(incompatibility)
      122│ 
      123│                     # Back jumping erases all the assignments we did at the previous

  SolveFailure

  Because poetry-bug depends on scikit-learn (^0) which doesn't match any versions, version solving failed.

  at ~/.poetry/venv/lib/python3.9/site-packages/poetry/mixology/version_solver.py:315 in _resolve_conflict
      311│             )
      312│             self._log(f'{bang} which is caused by "{most_recent_satisfier.cause}"')
      313│             self._log(f"{bang} thus: {incompatibility}")
      314│ 
    → 315│         raise SolveFailure(incompatibility)
      316│ 
      317│     def _choose_package_version(self) -> Optional[str]:
      318│         """
      319│         Tries to select a version of a required package.

The following error occurred when trying to handle this error:


  Stack trace:

  11  ~/.poetry/venv/lib/python3.9/site-packages/cleo/application.py:330 in run
       328│ 
       329│             try:
     → 330│                 exit_code = self._run(io)
       331│             except Exception as e:
       332│                 if not self._catch_exceptions:

  10  ~/.poetry/venv/lib/python3.9/site-packages/poetry/console/application.py:180 in _run
       178│         self._load_plugins(io)
       179│ 
     → 180│         return super()._run(io)
       181│ 
       182│     def _configure_io(self, io: IO) -> None:

   9  ~/.poetry/venv/lib/python3.9/site-packages/cleo/application.py:425 in _run
       423│                 io.set_input(ArgvInput(argv))
       424│ 
     → 425│         exit_code = self._run_command(command, io)
       426│         self._running_command = None
       427│ 

   8  ~/.poetry/venv/lib/python3.9/site-packages/cleo/application.py:467 in _run_command
       465│ 
       466│         if error is not None:
     → 467│             raise error
       468│ 
       469│         return event.exit_code

   7  ~/.poetry/venv/lib/python3.9/site-packages/cleo/application.py:451 in _run_command
       449│ 
       450│             if event.command_should_run():
     → 451│                 exit_code = command.run(io)
       452│             else:
       453│                 exit_code = ConsoleCommandEvent.RETURN_CODE_DISABLED

   6  ~/.poetry/venv/lib/python3.9/site-packages/cleo/commands/base_command.py:118 in run
       116│         io.input.validate()
       117│ 
     → 118│         status_code = self.execute(io)
       119│ 
       120│         if status_code is None:

   5  ~/.poetry/venv/lib/python3.9/site-packages/cleo/commands/command.py:85 in execute
        83│ 
        84│         try:
     →  85│             return self.handle()
        86│         except KeyboardInterrupt:
        87│             return 1

   4  ~/.poetry/venv/lib/python3.9/site-packages/poetry/console/commands/install.py:162 in handle
       160│         self._installer.verbose(self._io.is_verbose())
       161│ 
     → 162│         return_code = self._installer.run()
       163│ 
       164│         if return_code != 0:

   3  ~/.poetry/venv/lib/python3.9/site-packages/poetry/installation/installer.py:114 in run
       112│         local_repo = Repository()
       113│ 
     → 114│         return self._do_install(local_repo)
       115│ 
       116│     def dry_run(self, dry_run: bool = True) -> "Installer":

   2  ~/.poetry/venv/lib/python3.9/site-packages/poetry/installation/installer.py:251 in _do_install
       249│             )
       250│ 
     → 251│             ops = solver.solve(use_latest=self._whitelist).calculate_operations()
       252│         else:
       253│             self._io.write_line("Installing dependencies from lock file")

   1  ~/.poetry/venv/lib/python3.9/site-packages/poetry/puzzle/solver.py:77 in solve
        75│         with self._provider.progress():
        76│             start = time.time()
     →  77│             packages, depths = self._solve(use_latest=use_latest)
        78│             end = time.time()
        79│ 

  SolverProblemError

  Because poetry-bug depends on scikit-learn (^0) which doesn't match any versions, version solving failed.

  at ~/.poetry/venv/lib/python3.9/site-packages/poetry/puzzle/solver.py:146 in _solve
      142│             packages = result.packages
      143│         except OverrideNeeded as e:
      144│             return self.solve_in_compatibility_mode(e.overrides, use_latest=use_latest)
      145│         except SolveFailure as e:
    → 146│             raise SolverProblemError(e)
      147│ 
      148│         # NOTE passing explicit empty array for seen to reset between invocations during update + install cycle
      149│         results = dict(
      150│             depth_first_search(

In the above, it seems Poetry is searching for scikit-learn (>=0,<0.1) when given ^0. Whilst there is no scikit-learn=0.0.Z package, Poetry should actually search for scikit-learn (>=0,<1) according to the documentation.

[ESKYoung]

This seems to relate to issue #4153, and its related PR fix in python-poetry/poetry-core.

Looking at it, the fix was applied to poetry-core>=1.1.0a7, but the poetry.lock file in this repository is using poetry-core==1.1.0a6. Could this be updated for the next preview/release? Raised PR #5281 to resolve this.

[finswimmer]

Ah, you found the related issue. 👍 I was sure this was reported earlier but couldn't found the issue anymore (github search is a mess ...)

The install-poetry.py installer script doesn't use the lock file. So you just have to reinstall the Poetry pre-release and poetry-core 1.1.0a7 will be picked up as a dependency.

[ESKYoung]

Ah awesome, thanks @finswimmer — can confirm that this works now! 😄

I'll close this issue now — happy for the associated PR to be closed as well!

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.