T12955.hsig:1:11: error: [GHC-66004]
    Unexpected signature: ‘T12955’
    Suggested fix:
      Try passing -instantiated-with="T12955=<T12955>"
      replacing <T12955> as necessary.

T12955.hsig:1:11: error: [GHC-66004]
    Unexpected signature: ‘T12955’
    Suggested fix:
      Try adding ‘T12955’ to the ‘signatures’ field in your Cabal file.