Confusing error when trying to use with miri without run

[Imberflur]

Trying to use nextest with miri I ran:

cargo +nightly miri nextest

Which produces:

error: unexpected argument '--target-dir'

This led me to think there was some incompatibility between the versions when I was really just missing a run at the end.

[sunshowers]

Ah yeah, I can see that being confusing!

One way to fix this would be to implement #800.