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     StateVar-1.2
Starting     cabal-doctest-1.0.7
Starting     base-orphans-0.8.1
Starting     config-value-0.7.0.0
Failed to install config-value-0.7.0.0
Build log ( /home/builder/.cabal/logs/ghc-8.6.3/config-value-0.7.0.0-EyBlYNDXrSK1yXdt9aP9SC.log ):
cabal: Entering directory '/tmp/cabal-tmp-11381/config-value-0.7.0.0'
Configuring config-value-0.7.0.0...
cabal: The program 'happy' version ^>=1.19.12 is required but the version
found at /home/builder/.cabal/bin/happy is version 1.19.9

cabal: Leaving directory '/tmp/cabal-tmp-11381/config-value-0.7.0.0'
Starting     hashable-1.3.0.0
Building     StateVar-1.2
Building     base-orphans-0.8.1
Building     cabal-doctest-1.0.7
Building     hashable-1.3.0.0
Completed    base-orphans-0.8.1
Completed    StateVar-1.2
Completed    cabal-doctest-1.0.7
Completed    hashable-1.3.0.0
cabal: Error: some packages failed to install:
config-schema-1.2.0.0-2D6iQVUGpVi6UKcN2ZsKJJ depends on config-schema-1.2.0.0
which failed to install.
config-value-0.7.0.0-EyBlYNDXrSK1yXdt9aP9SC failed during the configure step.
The exception was:
ExitFailure 1