Setting up a sandboxed installation of GHC HEAD

[Jan Stolarek]

> You can just make cabal use a different GHC for compilation, etc.
What I need to do is compile a single source file and examine the Core and ASM dumps. It would be 
much more convenient if I could do this by simply invoking GHC from the command line instead of 
creating a fake cabal package for every source file I need to test.

Also, will there be no problems if I attempt to use with HEAD libraries compiled with 7.6.2? I 
can't check this at the moment.

Janek