simultaneous ghc versions

[Evan Laforge]

On Fri, Jul 31, 2015 at 11:26 AM, Herbert Valerio Riedel
<hvriedel at gmail.com> wrote:
> Btw, I simply prepend to the $PATH env variable, or pass the appropriate
> executable name to `cabal`'s
>
>    -w --with-compiler=PATH            give the path to a particular compiler

I don't understand, aren't they all in /usr/local/bin?  Or do you use
a version-specific prefix when installing each ghc version?

Also, ghc is not just the compiler, but also hsc2hs hpc runghc ghci
ghc-pkg haddock-ghc.  At the least, ghc-pkg has to be the right
version, but all of those are version specific since they'll break if
you remove their /usr/lib/ghc-version.