Yeah, I don't see any problems with using this. It's an unstable option so it could go away, but I think the more likely path is that it will improve. The commit adding this is pretty straightforward too, so easy to extend if something isn't quite right.
https://github.com/rust-lang/rust/pull/38699/filesWe might want to get involved in the process of stabilizing it?
We use 3 other unstable flags:
-Zallow-features - allows us to constrain rust features
-Zpanic_abort_tests - enables panic=abort tests
-Zdep-info-omit-d-target - removes the dep file from tracking itself
Only one of those (panic-abort-tests) is on a path to stabilizing. The other two aren't loadbearing in any way except making our lives easier.