aos-signature fails to build on GHC 8.6.1

[jkachmar]

aos-signature currently fails to build on GHC 8.6.1 with the following errors:

src/LSAG.hs:54:7: error:
    • Could not deduce (Control.Monad.Fail.MonadFail m)
        arising from a do statement
        with the failable pattern ‘(sK1 : sK2ToPrevSK)’
      from the context: MonadRandom m
        bound by the type signature for:
                   sign :: forall (m :: * -> *).
                           MonadRandom m =>
                           [ECDSA.PublicKey]
                           -> (ECDSA.PublicKey, ECDSA.PrivateKey)
                           -> ByteString
                           -> m (Integer, [Integer], ECC.Point)
        at src/LSAG.hs:(42,1)-(47,38)
      Possible fix:
        add (Control.Monad.Fail.MonadFail m) to the context of
          the type signature for:
            sign :: forall (m :: * -> *).
                    MonadRandom m =>
                    [ECDSA.PublicKey]
                    -> (ECDSA.PublicKey, ECDSA.PrivateKey)
                    -> ByteString
                    -> m (Integer, [Integer], ECC.Point)
    • In a stmt of a 'do' block:
        (sK1 : sK2ToPrevSK) <- replicateM (participants - 1)
                                 $ generateBetween 1 (n - 1)
      In the expression:
        do (sK1 : sK2ToPrevSK) <- replicateM (participants - 1)
                                    $ generateBetween 1 (n - 1)
           u <- generateBetween 1 (n - 1)
           let chK1 = genChallenge curve pubKeys y msg (gu u) (hu u)
           let reversedChKToChK1 = runChallenges k sK1 chK1 sK2ToPrevSK u y h
               chK = head reversedChKToChK1
           ....
      In a case alternative:
          Just k
            -> do (sK1 : sK2ToPrevSK) <- replicateM (participants - 1)
                                           $ generateBetween 1 (n - 1)
                  u <- generateBetween 1 (n - 1)
                  let chK1 = ...
                  ....
   |
54 |       (sK1:sK2ToPrevSK) <- replicateM (participants - 1) $ generateBetween 1 (n - 1)
   | 

cf. commercialhaskell/stackage#4119

[sdiehl]

Fixed in aos-signature-0.1.1