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     base-prelude-1.3
Starting     base-noprelude-4.12.0.0
Starting     colour-2.3.4
Starting     base-compat-0.10.5
Building     base-prelude-1.3
Building     base-noprelude-4.12.0.0
Building     colour-2.3.4
Building     base-compat-0.10.5
Completed    base-noprelude-4.12.0.0
Starting     dlist-0.8.0.6
Building     dlist-0.8.0.6
Completed    dlist-0.8.0.6
Starting     hashable-1.2.7.0
Building     hashable-1.2.7.0
Completed    base-compat-0.10.5
Starting     integer-logarithms-1.0.2.2
Completed    base-prelude-1.3
Starting     parser-combinators-1.0.2
Building     integer-logarithms-1.0.2.2
Completed    colour-2.3.4
Starting     primitive-0.6.4.0
Building     parser-combinators-1.0.2
Building     primitive-0.6.4.0
Completed    hashable-1.2.7.0
Starting     random-1.1
Building     random-1.1
Completed    integer-logarithms-1.0.2.2
Starting     shellmet-0.0.1
Building     shellmet-0.0.1
Completed    parser-combinators-1.0.2
Starting     tagged-0.8.6
Failed to install shellmet-0.0.1
Build log ( /home/builder/.cabal/logs/ghc-8.6.3/shellmet-0.0.1-EWpLHDmi6gpGZubC3ggCpA.log ):
cabal: Entering directory '/tmp/cabal-tmp-17719/shellmet-0.0.1'
Configuring shellmet-0.0.1...
Preprocessing library for shellmet-0.0.1..
Building library for shellmet-0.0.1..
[1 of 1] Compiling Shellmet
Preprocessing executable 'readme' for shellmet-0.0.1..
Building executable 'readme' for shellmet-0.0.1..
ghc: could not execute: markdown-unlit
cabal: Leaving directory '/tmp/cabal-tmp-17719/shellmet-0.0.1'
Starting     th-abstraction-0.2.11.0
Building     tagged-0.8.6
Building     th-abstraction-0.2.11.0
Completed    random-1.1
Completed    tagged-0.8.6
Completed    th-abstraction-0.2.11.0
Completed    primitive-0.6.4.0
cabal: Error: some packages failed to install:
shellmet-0.0.1-EWpLHDmi6gpGZubC3ggCpA failed during the building phase. The
exception was:
ExitFailure 1
summoner-1.3.0-9p9aBQmwLBKHQiZyA0hKhn depends on summoner-1.3.0 which failed
to install.