Tracking Issue for exclude-should-panic

[ehuss]

This is a tracking issue for the --exclude-should-panic flag of libtest.

This prevents tests annotated with the should_panic attribute from running.

Implementation: #58689

Unresolved Questions

• Is this useful for anyone? It was added for miri, but as of update README miri#1104, it appears miri no longer needs it.

[Mark-Simulacrum]

We had wanted this in #55861 (comment), but ultimately those tests were also disabled. IIRC, I also ran into the problem that usually using this in a non-internal way (e.g., for miri) you also want it for rustdoc.