Installing multiple versions of erlang on a machine?

[Matthew Palmer]

On Wed, Jul 28, 2010 at 12:30:38PM +0530, CHAITANYA CHALASANI wrote:
> We have production systems running on R13B04. I want to evaluate our
> programs on R14A meanwhile.
> How can I install more than version of erlang on the same machine and
> yet choose which one i want to use at the point of time?
> 
> Is there a direct solution for this? If not any workarounds?

You can almost certainly build multiple versions of Erlang, with different
installation and library paths.  The hassle involved, the possibility of
bugs and things not working as you'd expect in production (due to different
paths for things), and the need to go outside what the package management
system lets you do, all make this a fairly painful exercise.

I just spin up new VMs using KVM when I need to test this sort of thing;
automated builds make creating a new machine a low-cost operation, and it
ensures that your test environment matches production as closely as possible
at all times.

- Matt