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Haskell how to resolve this error: Unsupported extension: MultiWayIf

while trying to install the friday package, I got the error 

Preprocessing library friday-0.2.2.0...

src/Vision/Detector/Edge.hs:3:14: Unsupported extension: MultiWayIf
cabal: Error: some packages failed to install:
friday-0.2.2.0 failed during the building phase. The exception was:
ExitFailure 1

How to resolve this error?

I am using ghc version 7.4.1 and 

cabal-install version 0.14.0
using version 1.14.0 of the Cabal library
Solution

  • MultiWayIf was introduced in the 7.6 branch of GHC. You're going to have to upgrade the compiler or patch the library.