Resolving dependencies...
Starting     brotli-0.0.0.0
Starting     chs-deps-0.1.0.0
Starting     colour-2.3.5
Starting     bz2-1.0.1.0
Building     brotli-0.0.0.0
Building     chs-deps-0.1.0.0
Building     colour-2.3.5
Building     bz2-1.0.1.0
Completed    chs-deps-0.1.0.0
Starting     composition-prelude-3.0.0.2
Building     composition-prelude-3.0.0.2
Completed    brotli-0.0.0.0
Starting     digest-0.0.1.2
Building     digest-0.0.1.2
Completed    composition-prelude-3.0.0.2
Starting     dir-traverse-0.2.3.0
Building     dir-traverse-0.2.3.0
Completed    digest-0.0.1.2
Starting     dlist-1.0
Building     dlist-1.0
Completed    dir-traverse-0.2.3.0
Starting     lz4-hs-0.1.5.1
Failed to install lz4-hs-0.1.5.1
Build log ( /home/builder/.cabal/logs/ghc-8.10.2/lz4-hs-0.1.5.1-zKPfyqiSHa9AAXoV4GCTV.log ):
cabal: Entering directory '/tmp/cabal-tmp-2007/lz4-hs-0.1.5.1'
Configuring lz4-hs-0.1.5.1...
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-2007/lz4-hs-0.1.5.1'
Starting     lzlib-1.0.7.1
Building     lzlib-1.0.7.1
Completed    colour-2.3.5
Completed    dlist-1.0
Completed    bz2-1.0.1.0
Completed    lzlib-1.0.7.1
cabal: Error: some packages failed to install:
hstar-0.1.0.5-CYU6aGKT7HrFzbk5TrZLBT depends on hstar-0.1.0.5 which failed to
install.
lz4-hs-0.1.5.1-zKPfyqiSHa9AAXoV4GCTV failed during the configure step. The
exception was:
ExitFailure 1