GHC Installation Location

Mieszko Lis
Thu, 25 Oct 2001 20:22:25 -0400

On Thu, Oct 25, 2001 at 04:45:13PM -0700, Ashley Yakeley wrote:
> >I'm not sure this would be so good when you want to have two versions of ghc
> >installed on the same machine...
> Currently the Debian ghc5 package installs links such as /usr/bin/ghc 
> using the 'alternatives' system. You'd just need to add a 
> /usr/include/ghc one to that alternatives group.

Right, but if all ghcs always use /usr/include/ghc then you can only run the
ghc that is the `current alternative' -- if you try to run the other one, it
will find the wrong libraries (which may or may not work).  So, without root
intervention to change the current alternative, you could still only run
one, which makes having multiple versions installed a lot less useful.  And,
even if ghc itself did not use /usr/include/ghc, your multilingual makefile
would get the wrong includes if you used the non-current-alternative ghc.

-- Mieszko