Upstreams using specialized repos fail to concretize

[psakievich]

Steps to reproduce

Recently spack has stopped working with an upstream that we've been using for months. The upstream has it's own repo called cde where some package modifications are done.
Now when we try to concretize we get an Unknown namespace error.

spack config add upstreams:fails:install_tree:/upstream/with/custom/repo/spack/opt/spack
spack concretize 

Error message

spack -d concretize
[...]
 UnknownNamespaceError: Unknown namespace: cde
==> [2022-11-14-12:25:58.778921] Error: Unknown namespace: cde
Traceback (most recent call last):
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/main.py", line 1007, in main
    return _main(argv)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/main.py", line 962, in _main
    return finish_parse_and_run(parser, cmd_name, env_format_error)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/main.py", line 990, in finish_parse_and_run
    return _invoke_command(command, parser, args, unknown)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/main.py", line 639, in _invoke_command
    return_val = command(parser, args)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/cmd/concretize.py", line 45, in concretize
    concretized_specs = env.concretize(force=args.force, tests=tests)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/environment/environment.py", line 1279, in concretize
    return self._concretize_together(tests=tests)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/environment/environment.py", line 1332, in _concretize_together
    *self.user_specs, tests=tests
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/concretize.py", line 739, in concretize_specs_together
    return _concretize_specs_together_new(*abstract_specs, **kwargs)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/concretize.py", line 748, in _concretize_specs_together_new
    result = solver.solve(abstract_specs)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/solver/asp.py", line 2433, in solve
    result, _, _ = self.driver.solve(setup, specs, reuse=reusable_specs, output=output)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/solver/asp.py", line 627, in solve
    setup.setup(self, specs, reuse=reuse)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/solver/asp.py", line 1987, in setup
    self._facts_from_concrete_spec(reusable_spec, possible)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/solver/asp.py", line 1895, in _facts_from_concrete_spec
    self.impose(h, spec, body=True)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/solver/asp.py", line 1088, in impose
    imposed_constraints = self.spec_clauses(imposed_spec, body=body, required_from=name)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/solver/asp.py", line 1311, in spec_clauses
    clauses = self._spec_clauses(*args, **kwargs)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/solver/asp.py", line 1476, in _spec_clauses
    for virtual in dep.package.virtuals_provided:
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/spec.py", line 1639, in package
    self._package = spack.repo.path.get(self)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/repo.py", line 977, in get
    return self.repo_for_pkg(spec).get(spec)
  File "/home/psakiev/soft/spack-manager/spack/lib/spack/spack/repo.py", line 960, in repo_for_pkg
    raise UnknownNamespaceError(namespace, name=name)
spack.repo.UnknownNamespaceError: Unknown namespace: cde

Information on your system

• Spack: 0.19.0.dev0 (f92987b)
• Python: 3.7.5
• Platform: linux-rhel7-cascadelake
• Concretizer: clingo

General information

• I have run spack debug report and reported the version of Spack/Python/Platform
• I have searched the issues of this repo and believe this is not a duplicate
• I have run the failing commands in debug mode and reported the output

[psakievich]

@becker33 looks like this is due to #32434