Bogus "unused import" warning
DsMeta (in the source code for GHC itself), there's an import
import qualified OccName
-fwarn-unused-imports we get the warning
deSugar/DsMeta.hs:45:0: Warning: Module `OccName' is imported, but nothing from it is used, except perhaps instances visible in `OccName' To suppress this warning, use: import OccName()
But that's wrong: there are several uses of things imported from
I tried to reproduce this in a much smaller program, and failed, so something not entirely trivial is happening. Hence this ticket, to make sure we don't forget.