ghc/tests/typecheck/should_fail/tcfail039.stderr

   1
   2 tcfail039.hs:11:
   3     Ambiguous occurrence `=='
   4     It could refer to either `ShouldFail.==', defined at tcfail039.hs:7
   5                           or `PrelBase.==', imported from Prelude at tcfail039.hs:3 ()