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     random-1.1
Starting     primitive-0.7.0.0
Starting     transformers-compat-0.6.5
Building     random-1.1
Building     transformers-compat-0.6.5
Building     primitive-0.7.0.0
Completed    transformers-compat-0.6.5
Completed    random-1.1
Completed    primitive-0.7.0.0
Starting     MonadRandom-0.5.1.1
Building     MonadRandom-0.5.1.1
Completed    MonadRandom-0.5.1.1
Starting     random-shuffle-0.0.4
Building     random-shuffle-0.0.4
Completed    random-shuffle-0.0.4
Starting     ascii-holidays-0.1.0.0
Building     ascii-holidays-0.1.0.0
Failed to install ascii-holidays-0.1.0.0
Build log ( /home/builder/.cabal/logs/ghc-8.6.3/ascii-holidays-0.1.0.0-9fmHTEJdaAhH7OVmlXVFpm.log ):
cabal: Entering directory '/tmp/cabal-tmp-9001/ascii-holidays-0.1.0.0'
Configuring ascii-holidays-0.1.0.0...
Preprocessing executable 'ascii-holidays' for ascii-holidays-0.1.0.0..
Building executable 'ascii-holidays' for ascii-holidays-0.1.0.0..
[1 of 1] Compiling Main             ( Main.hs, dist/build/ascii-holidays/ascii-holidays-tmp/Main.o )

Main.hs:5:1: error:
    Could not find module ‘BashTree’
    Use -v to see a list of the files searched for.
  |
5 | import BashTree
  | ^^^^^^^^^^^^^^^

Main.hs:6:1: error:
    Could not find module ‘PerlTree’
    Use -v to see a list of the files searched for.
  |
6 | import PerlTree
  | ^^^^^^^^^^^^^^^
cabal: Leaving directory '/tmp/cabal-tmp-9001/ascii-holidays-0.1.0.0'
cabal: Error: some packages failed to install:
ascii-holidays-0.1.0.0-9fmHTEJdaAhH7OVmlXVFpm failed during the building
phase. The exception was:
ExitFailure 1