opam package conf-python-3.9.0.0 depends on the following system package that can no longer be found: python@3

[jordydickinson]

Output of opam config report:

# opam config report
# opam-version         2.1.5 
# self-upgrade         no
# system               arch=x86_64 os=macos os-distribution=homebrew os-version=12.7.1
# solver               builtin-mccs+glpk
# install-criteria     -removed,-count[avoid-version,changed],-count[version-lag,request],-count[version-lag,changed],-count[missing-depexts,changed],-changed
# upgrade-criteria     -removed,-count[avoid-version,changed],-count[version-lag,solution],-count[missing-depexts,changed],-new
# jobs                 3
# repositories         1 (http) (default repo at 25db7aa6)
# pinned               4 (git)
# current-switch       default
[WARNING] Opam package conf-python-3.9.0.0 depends on the following system
          package that can no longer be found: python@3
# ocaml:native         true
# ocaml:native-tools   true
# ocaml:native-dynlink true
# ocaml:stubsdir       /Users/jordydickinson/.opam/default/lib/ocaml/stublibs:/Users/jordydickinson/.opam/default/lib/ocaml
# ocaml:preinstalled   false
# ocaml:compiler       4.14.1

python@3 is already installed via Homebrew. Reinstalling the package has no effect. Adding the unversioned python, pip, etc. executables to $PATH has no effect.

[mseri]

I am trying a PR to mitigate this, but it is a known problem.

from an opam PR:

In the meantime, you can fix your setup by telling to opam that python@3 system package is well installed, using assume-depext feature: opam option depext-bypass='["python@3"]' --global