[Test] Small error output tweak to avoid misunderstandings
[Test] Small error output tweak to avoid misunderstandings

I was searching for e.g. `attributes.re` in `unit_test/` because the way the error was displayed led me to believe it was in that folder.

cristianoc/reason,chenglou/reason,cristianoc/reason,cristianoc/reason,yunxing/reason,let-def/reason,facebook/reason,facebook/reason,ak3n/reason,let-def/reason,ak3n/reason,let-def/reason,facebook/reason,yunxing/reason,yunxing/reason,chenglou/reason,ak3n/reason,yunxing/reason,chenglou/reason,ak3n/reason