Update 2: now uses writeFileAtomic from Cabal
This is a new patch for Ticket #199; it adds the "--one-shot" option.
A world file entry contains the package-name, package-version, and
user flags (if any).
For example, the file entry generated by
# cabal install stm-io-hooks --flags="-debug"
looks like this:
# stm-io-hooks -any --flags="-debug"
To rebuild/upgrade the packages in world (e.g. when updating the compiler)
use
cabal install world
Installing package 'foo' without adding it to the world file:
# cabal install foo --one-shot