[Nix-dev] Re: Multiple Profiles per User

[Ludovic Courtès]

Hello,

"Darcy Watkins" <DWatkins at tranzeo.com>
writes:

> The application is software development and multiple maintenance where
> you release one version of a product and then have to support a
> maintenance stream alongside of continued development.  In SVN/CVS
> scheme of things, this is having one project workspace be based on the
> trunk, and the other be based on a branch.
>
> 1.  I would like to be able to have each workspace be connected to its
> own profile.
> 2.  I would like the context to switch automatically as I switch back
> and forth between the two.
> 3.  I would like the choice to be part of what is checked into version
> control.

That appears to be a common application, and a useful one.

It would be possible to have individual `.nix' files containing
invocations of `stdenv.mkDerivation' that build the dependencies of your
software project.  These files could be versioned within the project but
most likely, they would also refer to a large subset of the Nixpkgs
subtree, the subset of dependencies that are of lesser importance to the
software project (e.g., libc, gcc, etc.).

Running the test suite in the right environment would be a matter of
setting $PATH to point to the exact dependencies you want (under
`/nix/store').

Thanks,
Ludovic.