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     load-font-0.1.0.2
Starting     primitive-0.7.0.0
Building     primitive-0.7.0.0
Building     load-font-0.1.0.2
Completed    load-font-0.1.0.2
Completed    primitive-0.7.0.0
Starting     vector-0.12.0.3
Building     vector-0.12.0.3
Completed    vector-0.12.0.3
Starting     fltkhs-0.8.0.2
Failed to install fltkhs-0.8.0.2
Build log ( /home/builder/.cabal/logs/ghc-8.6.3/fltkhs-0.8.0.2-8GLaqWu8CF3Je3z1iOCPwv.log ):
cabal: Entering directory '/tmp/cabal-tmp-19158/fltkhs-0.8.0.2'
[1 of 1] Compiling Main             ( /tmp/cabal-tmp-19158/fltkhs-0.8.0.2/dist/setup/setup.hs, /tmp/cabal-tmp-19158/fltkhs-0.8.0.2/dist/setup/Main.o )
Linking /tmp/cabal-tmp-19158/fltkhs-0.8.0.2/dist/setup/setup ...
Running autoconf ...
autoconf: rawSystem: runInteractiveProcess: exec: does not exist (No such file or directory)
cabal: Leaving directory '/tmp/cabal-tmp-19158/fltkhs-0.8.0.2'
cabal: Error: some packages failed to install:
fltkhs-0.8.0.2-8GLaqWu8CF3Je3z1iOCPwv failed during the configure step. The
exception was:
ExitFailure 1
fltkhs-themes-0.2.0.2-L8dxGE3jc8tHIvEKIsQAx9 depends on fltkhs-themes-0.2.0.2
which failed to install.