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     cabal-doctest-1.0.8
Starting     call-stack-0.2.0
Starting     base-orphans-0.8.1
Starting     dual-0.1.1.1
Building     call-stack-0.2.0
Building     dual-0.1.1.1
Building     base-orphans-0.8.1
Building     cabal-doctest-1.0.8
Completed    call-stack-0.2.0
Starting     primitive-0.7.0.0
Completed    base-orphans-0.8.1
Starting     tagged-0.8.6
Completed    dual-0.1.1.1
Starting     util-0.1.17.0
Building     primitive-0.7.0.0
Building     tagged-0.8.6
Building     util-0.1.17.0
Completed    cabal-doctest-1.0.8
Completed    util-0.1.17.0
Starting     foldable1-0.1.0.0
Completed    tagged-0.8.6
Starting     hs-functors-0.1.6.0
Building     foldable1-0.1.0.0
Building     hs-functors-0.1.6.0
Completed    foldable1-0.1.0.0
Completed    hs-functors-0.1.6.0
Completed    primitive-0.7.0.0
Starting     vector-0.12.0.3
Building     vector-0.12.0.3
Completed    vector-0.12.0.3
Downloading  lens-core-0.1.0.3
Downloaded   lens-core-0.1.0.3
Starting     lens-core-0.1.0.3
Building     lens-core-0.1.0.3
Completed    lens-core-0.1.0.3