testsuite/tests/typecheck/should_fail/tcfail181.stderr


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tcfail181.hs:17:9:
    Ambiguous type variable `m0' in the constraint:
      (Monad m0) arising from a use of `foo'
    Probable fix: add a type signature that fixes these type variable(s)
    In the expression: foo
    In the expression: foo {bar = return True}
    In an equation for `wog': wog x = foo {bar = return True}