Warning: The install command is a part of the legacy v1 style of cabal usage. Please switch to using either the new project style and the new-install command or the legacy v1-install alias as new-style projects will become the default in the next version of cabal-install. Please file a bug if you cannot replicate a working v1- use case with the new-style commands. For more information, see: https://wiki.haskell.org/Cabal/NewBuild Resolving dependencies... Starting colour-2.3.5 Starting dir-traverse-0.2.2.3 Starting composition-prelude-2.0.5.0 Starting bz2-1.0.0.2 Building composition-prelude-2.0.5.0 Building colour-2.3.5 Building bz2-1.0.0.2 Building dir-traverse-0.2.2.3 Completed dir-traverse-0.2.2.3 Starting lz4-hs-0.1.4.0 Completed composition-prelude-2.0.5.0 Starting lzlib-1.0.6.0 Failed to install lz4-hs-0.1.4.0 Build log ( /home/builder/.cabal/logs/ghc-8.6.3/lz4-hs-0.1.4.0-4Bysk7K3HzIFJZvPEJAGnV.log ): cabal: Entering directory '/tmp/cabal-tmp-9312/lz4-hs-0.1.4.0' Configuring lz4-hs-0.1.4.0... cabal: The program 'c2hs' version >=0.28.6 is required but the version found at /usr/bin/c2hs is version 0.28.3 cabal: Leaving directory '/tmp/cabal-tmp-9312/lz4-hs-0.1.4.0' Starting lzma-0.0.0.3 Building lzlib-1.0.6.0 Building lzma-0.0.0.3 Completed lzma-0.0.0.3 Completed colour-2.3.5 Completed bz2-1.0.0.2 Completed lzlib-1.0.6.0 cabal: Error: some packages failed to install: hstar-0.1.0.0-5kufzbnJC6U1U6OCxyUfuP depends on hstar-0.1.0.0 which failed to install. lz4-hs-0.1.4.0-4Bysk7K3HzIFJZvPEJAGnV failed during the configure step. The exception was: ExitFailure 1