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-2.4.1.0
Building     Cabal-2.4.1.0
Completed    Cabal-2.4.1.0
Downloading  first-class-instances-0.1.0.0
Downloaded   first-class-instances-0.1.0.0
Starting     first-class-instances-0.1.0.0
Building     first-class-instances-0.1.0.0
Completed    first-class-instances-0.1.0.0