Eu tentei instalar o Hlint pela primeira vez.cabal install hlint mas então eu recebi o erro:

cabal: Error: some packages failed to install:
cpphs-1.20.2 depends on old-time-1.1.0.3 which failed to install.
haskell-src-exts-1.18.2 depends on old-time-1.1.0.3 which failed to install.
hlint-1.9.37 depends on old-time-1.1.0.3 which failed to install.
old-time-1.1.0.3 failed during the configure step. The exception was:
ExitFailure 77

Então tentei instalar o ghc-mod, pois li que o hlint é uma dependência desse pacote (?). Pensando que isso pode resolver o problema. Então eu fizcabal install ghc-mod o que me deu o erro.

cabal: Error: some packages failed to install:
cpphs-1.20.2 depends on old-time-1.1.0.3 which failed to install.
ghc-mod-5.6.0.0 depends on old-time-1.1.0.3 which failed to install.
haskell-src-exts-1.17.1 depends on old-time-1.1.0.3 which failed to install.
hlint-1.9.35 depends on old-time-1.1.0.3 which failed to install.
old-time-1.1.0.3 failed during the configure step. The exception was:
ExitFailure 77

Então parece ser o mesmo problema, em torno do meu pacoteold-time-1.1.0.3.