map -package:base -is:exact -is:exact -package:unordered-containers -package:bytestring -package:text -package:Cabal is:module -package:express package:stack
A sourcemap maps a package name to how it should be built, including
source code, flags, options, etc. This module contains various stages
of source map construction. See the build_overview.md doc for
details on these stages.