error messages expose a dependency relationship between a and a{marker}

[BurntSushi]

For example:

  x No solution found when resolving dependencies:
  `-> Because fork-overlapping-markers-a{python_version == '3.12'}==1.0.0 depends on fork-overlapping-markers-a==1.0.0 and fork-overlapping-markers==0.0.0 depends on fork-overlapping-markers-a{python_version == '3.12'}==1.0.0, we
      can conclude that fork-overlapping-markers==0.0.0 and fork-overlapping-markers-a{python_version > '3.12'}==2.0.0 are incompatible.
      And because fork-overlapping-markers==0.0.0 depends on fork-overlapping-markers-a{python_version > '3.12'}==2.0.0, we can conclude that fork-overlapping-markers==0.0.0 cannot be used.
      And because only fork-overlapping-markers==0.0.0 is available and project==0.1.0 depends on fork-overlapping-markers, we can conclude that project==0.1.0 cannot be used.
      And because only project==0.1.0 is available and you require project, we can conclude that the requirements are unsatisfiable.

Specifically:

Because fork-overlapping-markers-a{python_version == '3.12'}==1.0.0 depends on fork-overlapping-markers-a==1.0.0

If one is familiar with internals, this makes sense, because we have specific "marker" dependencies and "normal" dependencies, and they have a dependency relationship with one another. But from an end user perspective, they probably should be treated as just one package.

[zanieb]

Seems clearer than #5612

[BurntSushi]

Haha whoops! Totally missed that one.

[charliermarsh]

Does anyone have an example that produces this?

[BurntSushi]

I think pretty much anything that doesn't produce a resolution and involves markers will do:

$ cat /tmp/requirements.in
iniconfig
iniconfig==2.0.0 ; python_version > '3.12'
iniconfig==1.0.0 ; python_version == '3.12'

$ uv pip compile /tmp/requirements.in --universal
  x No solution found when resolving dependencies:
  `-> Because iniconfig{python_version > '3.12'}==2.0.0 depends on iniconfig==2.0.0 and you require iniconfig{python_version > '3.12'}==2.0.0, we can conclude that your requirements and iniconfig{python_version == '3.12'}==1.0.0
      are incompatible.
      And because you require iniconfig{python_version == '3.12'}==1.0.0, we can conclude that the requirements are unsatisfiable.

Although I suppose this will stop producing an error once overlapping marker support lands. :P

[charliermarsh]

Awesome thank you :) I was having trouble getting this exact form to appear.