T12955.hsig:1:11: error:
    Unexpected signature: ‘T12955’
    (Try passing -instantiated-with="T12955=<T12955>"
     replacing <T12955> as necessary.)

T12955.hsig:1:11: error:
    Unexpected signature: ‘T12955’
    (Try adding ‘T12955’ to the ‘signatures’ field in your Cabal file.)