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     integer-logarithms-1.0.2.2
Starting     hashable-1.2.7.0
Starting     parser-combinators-1.0.1
Starting     primitive-0.6.4.0
Building     integer-logarithms-1.0.2.2
Building     parser-combinators-1.0.1
Building     primitive-0.6.4.0
Building     hashable-1.2.7.0
Completed    integer-logarithms-1.0.2.2
Completed    parser-combinators-1.0.1
Completed    hashable-1.2.7.0
Starting     case-insensitive-1.2.0.11
Starting     unordered-containers-0.2.9.0
Building     case-insensitive-1.2.0.11
Building     unordered-containers-0.2.9.0
Completed    case-insensitive-1.2.0.11
Completed    unordered-containers-0.2.9.0
Completed    primitive-0.6.4.0
Starting     scientific-0.3.6.2
Building     scientific-0.3.6.2
Completed    scientific-0.3.6.2
Starting     megaparsec-7.0.4
Building     megaparsec-7.0.4
Completed    megaparsec-7.0.4
Starting     tomland-1.0.0
Building     tomland-1.0.0
Failed to install tomland-1.0.0
Build log ( /home/builder/.cabal/logs/ghc-8.6.3/tomland-1.0.0-5cTa4vzPBqUGeLiDr4wN5d.log ):
cabal: Entering directory '/tmp/cabal-tmp-30399/tomland-1.0.0'
Configuring tomland-1.0.0...
Preprocessing library for tomland-1.0.0..
Building library for tomland-1.0.0..
[ 1 of 19] Compiling Toml.Bi.Monad
[ 2 of 19] Compiling Toml.Parser.Core
[ 3 of 19] Compiling Toml.Parser.String
[ 4 of 19] Compiling Toml.PrefixTree
[ 5 of 19] Compiling Toml.Type.Value
[ 6 of 19] Compiling Toml.Type.AnyValue
[ 7 of 19] Compiling Toml.Type.UValue
[ 8 of 19] Compiling Toml.Type.TOML
[ 9 of 19] Compiling Toml.Type
[10 of 19] Compiling Toml.Printer
[11 of 19] Compiling Toml.Parser.Value
[12 of 19] Compiling Toml.Parser.TOML
[13 of 19] Compiling Toml.Parser
[14 of 19] Compiling Toml.Edsl
[15 of 19] Compiling Toml.Bi.Map
[16 of 19] Compiling Toml.Bi.Code
[17 of 19] Compiling Toml.Bi.Combinators
[18 of 19] Compiling Toml.Bi
[19 of 19] Compiling Toml
Preprocessing executable 'play-tomland' for tomland-1.0.0..
Building executable 'play-tomland' for tomland-1.0.0..
[1 of 1] Compiling Main             ( examples/Playground.hs, dist/build/play-tomland/play-tomland-tmp/Main.o )
Linking dist/build/play-tomland/play-tomland ...
Preprocessing executable 'readme' for tomland-1.0.0..
Building executable 'readme' for tomland-1.0.0..
ghc: could not execute: markdown-unlit
cabal: Leaving directory '/tmp/cabal-tmp-30399/tomland-1.0.0'
cabal: Error: some packages failed to install:
tomland-1.0.0-5cTa4vzPBqUGeLiDr4wN5d failed during the building phase. The
exception was:
ExitFailure 1