This is the Stackage LTS version, which is compatible with ansi-terminal 0.8. * gnu/packages/haskell.scm (ghc-concurrent-output): Downgrade to 1.10.9 and use ghc-ansi-terminal-0.8.
This is the Stackage LTS version, which is compatible with ansi-terminal 0.8. * gnu/packages/haskell.scm (ghc-concurrent-output): Downgrade to 1.10.9 and use ghc-ansi-terminal-0.8.