Error in Environment.matching_specs() method #23333
Description
Today I hit an error in this line. The problem there is that root_matches is a dictionary mapping concrete specs to abstract specs, but it is indexed with an integer.
I hit this while attempting to use matching_spec() in #22657, but you can also make it happen using the spack location command (or probably any command that uses spack.cmd.matching_spec_from_env(spec)).
Steps to reproduce the issue
It seems you need to have an environment where a particular package appears both as a root and a dependency (so concretized separately), but that might not be the complete necessary/sufficient set of conditions. To create an example problem environment:
$ spack env create foo
$ spack env activate foo
$ spack add readline
$ spack add ncurses ~termlib
$ spack concretizeNow the foo environment contains two ncurses specs.
Error Message
To cause the error:
$ spack -d location -s ncurses
==> [2021-04-28-15:41:16.385703] Imported location from built-in commands
==> [2021-04-28-15:41:16.387569] Imported location from built-in commands
==> [2021-04-28-15:41:16.388594] Reading config file /projects/spack/etc/spack/defaults/repos.yaml
==> [2021-04-28-15:41:16.392801] Reading config file /projects/spack/var/spack/environments/blah/spack.yaml
Traceback (most recent call last):
File "/projects/spack/bin/spack", line 76, in <module>
sys.exit(spack.main.main())
File "/projects/spack/lib/spack/spack/main.py", line 772, in main
return _invoke_command(command, parser, args, unknown)
File "/projects/spack/lib/spack/spack/main.py", line 496, in _invoke_command
return_val = command(parser, args)
File "/projects/spack/lib/spack/spack/cmd/location.py", line 112, in location
spec = spack.cmd.matching_spec_from_env(spec)
File "/projects/spack/lib/spack/spack/cmd/__init__.py", line 192, in matching_spec_from_env
return env.matching_spec(spec) or spec.concretized()
File "/projects/spack/lib/spack/spack/environment.py", line 1588, in matching_spec
return root_matches[0][1]
KeyError: 0Information on your system
$ spack debug report
* **Spack:** 0.16.1-2415-ceacc6706f
* **Python:** 3.6.9
* **Platform:** linux-ubuntu18.04-haswell
* **Concretizer:** original
Additional information
- I have run
spack debug reportand 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