Resolving dependencies...
Downloading constraints-0.1...
Warning: constraints.cabal: Unexpected section 'other-extensions' on line 22
Configuring constraints-0.1...
Building constraints-0.1...
Preprocessing library constraints-0.1...
[1 of 3] Compiling Data.Constraint  ( Data/Constraint.hs, dist/build/Data/Constraint.o )

Data/Constraint.hs:38:14:
    Not in scope: type constructor or class ‘Constraint’
Failed to install constraints-0.1
cabal: Error: some packages failed to install:
constraints-0.1 failed during the building phase. The exception was:
ExitFailure 1