Previously, only the existence of a duplicate signature was reported:

  ErrorMultipleSignature.curry, line 1.1:
      More than one type signature for `f'

Now, the occurrences are additionally reported:

  ErrorMultipleSignature.curry, line 1.1:
      More than one type signature for `f' at:
        ErrorMultipleSignature.curry, line 1.1
        ErrorMultipleSignature.curry, line 3.1
        ErrorMultipleSignature.curry, line 6.1