mcbackend doesn't install with `uv pip install`

[edschofield]

With a clean miniconda environment (Python 3.10 or Python 3.12), mcbackend doesn't install using uv:

$ uv pip install mcbackend

Output:

Using Python 3.12.11 environment at: /opt/anaconda3/envs/pymc_mcbackend
  × No solution found when resolving dependencies:
  ╰─▶ Because there is no version of betterproto==2.0.0b3 and mcbackend<=0.1.1 depends on betterproto==2.0.0b3, we can conclude that
      mcbackend<=0.1.1 cannot be used.
      And because only the following versions of mcbackend are available:
          mcbackend==0.1.0
          mcbackend==0.1.1
          mcbackend==0.1.2
          mcbackend==0.1.3
          mcbackend==0.2.0
          mcbackend==0.2.1
          mcbackend==0.2.2
          mcbackend==0.2.3
          mcbackend==0.2.4
          mcbackend==0.2.5
          mcbackend==0.2.6
          mcbackend==0.2.7
          mcbackend==0.3.0
          mcbackend==0.4.0
          mcbackend==0.5.0
          mcbackend==0.5.1
          mcbackend==0.5.2
          mcbackend==0.5.3
      we can conclude that mcbackend<0.1.2 cannot be used. (1)

      Because there is no version of betterproto==2.0.0b4 and mcbackend>=0.1.2,<=0.2.0 depends on betterproto==2.0.0b4, we can
      conclude that mcbackend>=0.1.2,<=0.2.0 cannot be used.
      And because we know from (1) that mcbackend<0.1.2 cannot be used, we can conclude that mcbackend<0.2.1 cannot be used. (2)

      Because there is no version of betterproto==2.0.0b5 and mcbackend>=0.2.1,<=0.5.0 depends on betterproto==2.0.0b5, we can
      conclude that mcbackend>=0.2.1,<=0.5.0 cannot be used.
      And because we know from (2) that mcbackend<0.2.1 cannot be used, we can conclude that mcbackend<0.5.1 cannot be used. (3)

      Because there is no version of betterproto==2.0.0b6 and mcbackend>=0.5.1,<=0.5.2 depends on betterproto==2.0.0b6, we can
      conclude that mcbackend>=0.5.1,<=0.5.2 cannot be used.
      And because we know from (3) that mcbackend<0.5.1 cannot be used, we can conclude that mcbackend<0.5.3 cannot be used. (4)

      Because there is no version of betterproto==2.0.0b7 and mcbackend==0.5.3 depends on betterproto==2.0.0b7, we can conclude that
      mcbackend==0.5.3 cannot be used.
      And because we know from (4) that mcbackend<0.5.3 cannot be used, we can conclude that all versions of mcbackend cannot be used.
      And because you require mcbackend, we can conclude that your requirements are unsatisfiable.

      hint: `betterproto` was requested with a pre-release marker (e.g., betterproto==2.0.0b3), but pre-releases weren't enabled (try:
      `--prerelease=allow`)

Noticed with @zaxtax at the PyData Amsterdam 2025 sprints.

[edschofield]

Note that this works:

uv pip install --prerelease=allow mcbackend

[michaelosthege]

Looks like python-betterproto continued development under a new name: python-betterproto2 in https://github.com/betterproto/python-betterproto2 but they're still not doing releases that aren't marked pre-release :/

I guess the dependency should be switched to python-betterproto2, but unfortunately --prerelease=allow mcbackend would still be required.