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     microlens-0.4.11.2
Starting     reflection-2.1.4
Starting     vinyl-0.11.0
Starting     primitive-0.7.0.0
Building     microlens-0.4.11.2
Building     reflection-2.1.4
Building     vinyl-0.11.0
Building     primitive-0.7.0.0
Completed    microlens-0.4.11.2
Completed    reflection-2.1.4
Completed    vinyl-0.11.0
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  backprop-0.2.6.3
Downloaded   backprop-0.2.6.3
Starting     backprop-0.2.6.3
Building     backprop-0.2.6.3
Completed    backprop-0.2.6.3