spack test leaves behind config.yaml file

[adamjstewart]

When I run spack test, it leaves behind a config.yaml that shouldn't be there.

Steps to reproduce the issue

$ cat ~/.spack/config.yaml
cat: /Users/Adam/.spack/config.yaml: No such file or directory
$ spack test
...
$ cat ~/.spack/config.yaml 
config:
  build_stage: /private/var/folders/21/hwq39zyj4g36x6zjfyl5l8080000gn/T/pytest-of-Adam/pytest-1/mock-stage0

Information on your system

• macOS 10.14.6
• Python 3.7.3

This may also be related to #12647

[adamjstewart]

Confirmed that this function is responsible:
https://github.com/spack/spack/blob/develop/lib/spack/spack/test/conftest.py#L132,L158

[adamjstewart]

Even worse, if you have an existing build_stage set in your user-level config.yaml, it gets overwritten.

[adamjstewart]

It looks like this function was added in #12072. @tldahlgren can you take a look? The only fix I've found so far is to comment-out the entire first part of the if-statement, but that's probably there for a reason.

[tldahlgren]

See #12857

[scheibelp]

Closing this as a duplicate of #12798. Feel free to reopen if that does not seem to be the case to you. I am updating the title of that issue to make it clearer.