`cabal list` is not v2-aware

[gbaz]

as per https://stackoverflow.com/questions/57932348/cabal-install-works-but-cabal-list-does-not-find-package

cabal list shows which libraries are installed in the ghc pkgdb, but does not show libraries that are "installed" via global env files.

cabal list easyplot

• easyplot Synopsis: A tiny plotting library, utilizes gnuplot for plotting. Default available version: 1.0 Installed versions: [ Not installed ] <<<<<<<<<<<<< NOTE Homepage: http://hub.darcs.net/scravy/easyplot License: MIT