- -- no instance decls). It may be that we import M solely to
- -- ensure that M's orphan instance decls (or those in its imports)
- -- are visible to people who import this module. Sigh. There's
- -- really no good way to detect this, so the error message is weakened
+ -- no instance decls, or This contains no code). It may be
+ -- that we import M solely to ensure that M's orphan instance
+ -- decls (or those in its imports) are visible to people who
+ -- import This. Sigh.
+ -- There's really no good way to detect this, so the error message
+ -- in RnEnv.warnUnusedModules is weakened instead