x.py test with non-existent test directory should error

[Havvy]

./x.py test does-not-exist should spit out an error instead of being successful.

cc @GuillaumeGomez

[PlasmaPower]

This was confusing to me when I tried to specify a file for ./x.py test and it did nothing. 👍

[GuillaumeGomez]

@Mark-Simulacrum: Still no news on this?

[Mark-Simulacrum]

Well, I believe it'll be fixed within #43059. However, if someone would like to implement this, adding logic here https://github.com/rust-lang/rust/blob/master/src/bootstrap/step.rs#L1212 to check that all indices in the path array were visited seems fairly straightforward. I'll mark as E-mentor and unassign myself.

[GuillaumeGomez]

Well, I wanted to do it myself. :p