Channel priority is not used for recursive dependencies.

[hameerabbasi]

Checks

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pixi, using pixi --version.

Reproducible example

[project]
authors = ["Hameer Abbasi <[email protected]>"]
channels = ["conda-forge", "conda-forge/label/llvm_rc"]
description = "Add a short description here"
name = "repro"
platforms = ["osx-arm64"]
version = "0.1.0"

[tasks]

[dependencies]
numba = ">=0.54,<0.61"
mlir-python-bindings = { version = "19.*", channel = "conda-forge/label/llvm_rc" }

then pixi shell. Output:

  × failed to solve the conda requirements of 'default' 'osx-arm64'
  ╰─▶ Cannot solve the request because of: The following packages are incompatible
      └─ mlir-python-bindings 19.* cannot be installed because there are no viable options:
         └─ mlir-python-bindings 19.1.0.rc3 | 19.1.0.rc3 | 19.1.0.rc3 | 19.1.0.rc3 would require
            └─ mlir 19.1.0.rc3.*, which cannot be installed because there are no viable options:
               └─ mlir 19.1.0.rc3 is excluded because due to strict channel priority not using this option from: 'https://conda.anaconda.org/conda-forge/label/
      llvm_rc/'

Flipping around the channel prio gives:

  × failed to solve the conda requirements of 'default' 'osx-arm64'
  ╰─▶ Cannot solve the request because of: The following packages are incompatible
      └─ numba >=0.54,<0.61 cannot be installed because there are no viable options:
         ├─ numba 0.60.0 | 0.60.0 | 0.60.0 | 0.60.0 would require
         │  └─ llvmlite >=0.43.0,<0.44.0a0, which cannot be installed because there are no viable options:
         │     └─ llvmlite 0.43.0 | 0.43.0 | 0.43.0 | 0.43.0 | 0.43.0 | 0.43.0 | 0.43.0 | 0.43.0 | 0.43.0 would require
         │        └─ libllvm14 >=14.0.6,<14.1.0a0, which cannot be installed because there are no viable options:
         │           └─ libllvm14 14.0.6 | 14.0.6 | 14.0.6 | 14.0.6 | 14.0.6 is excluded because due to strict channel priority not using this option from: 'https://
      conda.anaconda.org/conda-forge/'
         ├─ numba 0.59.0 | 0.59.0 | 0.59.0 | 0.59.0 | 0.59.0 | 0.59.0 | 0.59.0 | 0.59.1 | 0.59.1 | 0.59.1 | 0.59.1 would require
         │  └─ llvmlite >=0.42.0,<0.43.0a0, which cannot be installed because there are no viable options:
         │     └─ llvmlite 0.42.0 | 0.42.0 | 0.42.0 | 0.42.0 | 0.42.0 | 0.42.0 | 0.42.0 would require
         │        └─ libllvm14 >=14.0.6,<14.1.0a0, which cannot be installed because there are no viable options:
         ├─ numba 0.58.1 | 0.58.1 | 0.58.1 | 0.58.1 | 0.58.1 | 0.58.1 | 0.58.1 | 0.58.1 would require
         │  └─ llvmlite >=0.41.1,<0.42.0a0, which cannot be installed because there are no viable options:
         │     └─ llvmlite 0.41.1 | 0.41.1 | 0.41.1 | 0.41.1 would require
         │        └─ libllvm14 >=14.0.6,<14.1.0a0, which cannot be installed because there are no viable options:
         ├─ numba 0.57.0 | 0.57.0 | 0.57.0 | 0.57.0 | 0.57.0 | 0.57.0 | 0.57.0 | 0.57.0 | 0.57.0 | 0.57.0 | 0.57.0 | 0.57.0 | 0.57.1 | 0.57.1 | 0.57.1 | 0.57.1 would
      require
         │  └─ llvmlite >=0.40.0,<0.41.0a0, which cannot be installed because there are no viable options:
         │     └─ llvmlite 0.40.0 | 0.40.0 | 0.40.0 | 0.40.0 | 0.40.1 | 0.40.1 | 0.40.1 | 0.40.1 would require
         │        └─ libllvm14 >=14.0.6,<14.1.0a0, which cannot be installed because there are no viable options:
         ├─ numba 0.56.2 | 0.56.2 | 0.56.2 | 0.56.2 | 0.56.2 | 0.56.2 | 0.56.3 | 0.56.3 | 0.56.3 | 0.56.4 | 0.56.4 | 0.56.4 | 0.56.4 | 0.56.4 | 0.56.4 would require
         │  └─ llvmlite >=0.39.1,<0.40.0a0, which cannot be installed because there are no viable options:
         │     └─ llvmlite 0.39.1 | 0.39.1 | 0.39.1 | 0.39.1 | 0.39.1 | 0.39.1 would require
         │        └─ libllvm11 >=11.1.0,<11.2.0a0, which cannot be installed because there are no viable options:
         │           └─ libllvm11 11.1.0 | 11.1.0 | 11.1.0 | 11.1.0 | 11.1.0 | 11.1.0 is excluded because due to strict channel priority not using this option from:
      'https://conda.anaconda.org/conda-forge/'
         ├─ numba 0.55.2 | 0.55.2 | 0.55.2 would require
         │  └─ llvmlite >=0.38.1,<0.39.0a0, which cannot be installed because there are no viable options:
         │     └─ llvmlite 0.38.1 | 0.38.1 | 0.38.1 would require
         │        └─ libllvm11 >=11.1.0,<11.2.0a0, which cannot be installed because there are no viable options:
         ├─ numba 0.55.0 | 0.55.0 | 0.55.0 | 0.55.1 | 0.55.1 | 0.55.1 | 0.55.1 | 0.55.1 | 0.55.1 would require
         │  └─ llvmlite >=0.38.0,<0.39.0a0, which cannot be installed because there are no viable options:
         │     └─ llvmlite 0.38.0 | 0.38.0 | 0.38.0 | 0.38.0 | 0.38.0 | 0.38.0 would require
         │        └─ libllvm11 >=11.1.0,<11.2.0a0, which cannot be installed because there are no viable options:
         └─ numba 0.54.0 | 0.54.0 | 0.54.1 | 0.54.1 would require
            └─ llvmlite >=0.37.0,<0.38.0a0, which cannot be installed because there are no viable options:
               └─ llvmlite 0.37.0 | 0.37.0 | 0.37.0 | 0.37.0 | 0.37.0 would require
                  └─ libllvm11 >=11.1.0,<11.2.0a0, which cannot be installed because there are no viable options:

Issue description

I think the dependencies of mlir-python-bindings should use the conda-forge/label/llvm_rc channel at a higher priority than the conda-forge label, which doesn't seem to be the case from the first error, otherwise one would always need to specify the whole dependency tree when installing a dep from another channel.

In addition, the ABI issues mentioned in https://pixi.sh/latest/advanced/channel_priority/ don't apply to this case; IMO they would only be exacerbated.

Expected behavior

The environment should solve in the first case (without channel prios flipped).