When accessing configuration data using spack.config.[gs]et at some point before test setup, something goes wrong and the test configuration will not be set up properly, leading to test failures. I encountered this in #17229 because it introduces spack.config.get calls in Spack's main function. However, it is enough to enable debugging to reproduce the problem.

Steps to reproduce the issue

$ spack -d test -k test_exclude_specs

Error Message

For some reason, the tests try to use my normal environment instead of the test environment:

E           spack.concretize.NoCompilersForArchError: No compilers found for operating system debian6 and target x86_64.
E           If previous installations have succeeded, the operating system may have been updated.
E           Compilers are defined for the following operating systems and targets:
E           	fedora32-x86_64
E               Run 'spack compiler find' to add compilers.

Information on your system

• Spack: 0.14.2-1557-096bd69a9
• Python: 3.8.3
• Platform: linux-fedora32-haswell

Additional 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