libmamba picks a build for the wrong Python version

[Zalnd]

Checklist

• I added a descriptive title
• I searched open reports and couldn't find a duplicate

What happened?

The conda install lxml==5.1.0 command gives the following output:

Channels:
 - conda-forge
 - defaults
Platform: win-64
Collecting package metadata (repodata.json): done
Solving environment: | warning  libmamba Added empty dependency for problem type SOLVER_RULE_UPDATE
failed

LibMambaUnsatisfiableError: Encountered problems while solving:
  - package lxml-5.1.0-py310hba208d0_0 requires python >=3.10,<3.11.0a0, but none of the providers can be installed

Could not solve for environment specs
The following packages are incompatible
├─ langchain is installable with the potential options
│  ├─ langchain [0.0.238|0.0.239|...|0.1.9] would require
│  │  └─ lxml >=4.9.2,<5.0.0 , which can be installed;
│  └─ langchain [0.0.136|0.0.142|...|0.0.190] would require
│     └─ openai >=0.0.0,<1.0.0 , which can be installed;
├─ lxml 5.1.0  is installable with the potential options
│  ├─ lxml 5.1.0 conflicts with any installable versions previously reported;
│  ├─ lxml 5.1.0 would require
│  │  └─ python >=3.10,<3.11.0a0 , which can be installed;
│  ├─ lxml 5.1.0 would require
│  │  └─ python >=3.12,<3.13.0a0 , which can be installed;
│  ├─ lxml 5.1.0 would require
│  │  └─ python >=3.8,<3.9.0a0 , which can be installed;
│  └─ lxml 5.1.0 would require
│     └─ python >=3.9,<3.10.0a0 , which can be installed;
├─ openai 1.17.1  is not installable because it conflicts with any installable versions previously reported;
└─ pin-1 is not installable because it requires
   └─ python 3.11.* , which conflicts with any installable versions previously reported.

It seems that libmamba picked up the lxml-5.1.0-py310hba208d0_0 build, but the installed Python version in this environment is 3.11.

Conda Info

conda version : 24.3.0
    conda-build version : not installed
         python version : 3.11.8.final.0
                 solver : libmamba (default)
       virtual packages : __archspec=1=bulldozer
                          __conda=24.3.0=0
                          __cuda=12.2=0
                          __win=0=0
           channel URLs : https://conda.anaconda.org/conda-forge/win-64
                          https://conda.anaconda.org/conda-forge/noarch
                          https://repo.anaconda.com/pkgs/main/win-64
                          https://repo.anaconda.com/pkgs/main/noarch
                          https://repo.anaconda.com/pkgs/r/win-64
                          https://repo.anaconda.com/pkgs/r/noarch
                          https://repo.anaconda.com/pkgs/msys2/win-64
                          https://repo.anaconda.com/pkgs/msys2/noarch
               platform : win-64
             user-agent : conda/24.3.0 requests/2.31.0 CPython/3.11.8 Windows/10 Windows/10.0.19045 solver/libmamba conda-libmamba-solver/24.1.0 libmambapy/1.5.8
          administrator : True
             netrc file : None
           offline mode : False

Conda Config

channels:
  - conda-forge
  - defaults

Conda list

It is a "test anything" environment with a lot of packages.

Additional Context

No response

[jaimergp]

It seems that libmamba picked up the lxml-5.1.0-py310hba208d0_0 build, but the installed Python version in this environment is 3.11.

That's just the (basic) error message. The elaborate one below gives you the full tree of problems. Can you still reproduce this? You can enable debug verbosity with -vvv to see what libsolv is doing behind the scenes and why it's not finding a solution.