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...
Warning: The following packages are likely to be broken by the reinstalls:
parsec-3.1.13.0
Cabal-2.4.0.1
Continuing even though the plan contains dangerous reinstalls.
Starting     clock-0.8
Starting     dlist-0.8.0.7
Downloading  safe-0.3.18
Starting     hashable-1.3.0.0
Downloaded   safe-0.3.18
Starting     safe-0.3.18
Building     dlist-0.8.0.7
Building     clock-0.8
Building     hashable-1.3.0.0
Building     safe-0.3.18
Completed    clock-0.8
Starting     semigroups-0.19.1
Completed    dlist-0.8.0.7
Starting     transformers-0.5.6.2
Building     semigroups-0.19.1
Building     transformers-0.5.6.2
Completed    hashable-1.3.0.0
Starting     unordered-containers-0.2.10.0
Completed    semigroups-0.19.1
Starting     extra-1.6.18
Completed    safe-0.3.18
Building     unordered-containers-0.2.10.0
Building     extra-1.6.18
Completed    extra-1.6.18
Completed    unordered-containers-0.2.10.0
Completed    transformers-0.5.6.2
Starting     writer-cps-transformers-0.5.6.1
Starting     mtl-2.2.2
Building     writer-cps-transformers-0.5.6.1
Building     mtl-2.2.2
Completed    writer-cps-transformers-0.5.6.1
Completed    mtl-2.2.2
Starting     writer-cps-mtl-0.1.1.6
Building     writer-cps-mtl-0.1.1.6
Completed    writer-cps-mtl-0.1.1.6
Downloading  intro-0.6.0.1
Downloaded   intro-0.6.0.1
Starting     intro-0.6.0.1
Building     intro-0.6.0.1
Completed    intro-0.6.0.1