[Nix-dev] Nix vs. Modules

[Ludovic Courtès]

Hello!

I had a discussion with my friendly local cluster admins.  They
currently use Modules [0].  Modules provide a convenient user interface
but are a pain for sysadmins, since sysadmins are responsible for
building the packages, writing and maintaining modules for them,
including maintaining different versions and variants (e.g., OpenMPI
compiled with different compilers, foobar compiled with different MPI
implementations, each compiled with different compilers).  And there’s
no such thing as rollback.

Nix is a win in many aspects.  However, its user interface is less
convenient: while ‘module load’ changes the environment in the current
shell, ‘nix-env --switch-profile’ changes the environment globally.

It would be fairly simple to provide a command akin to ‘module load’
that would set $PATH, etc. to point to a given profile, somewhat like
‘nix-store -r’ does.

Marc’s ‘myEnv’ seems to do something along these lines, but it’s
undocumented and looks somewhat cryptic to my untrained eyes.  ;-)
It’d be great if it could be polished and documented in the Nixpkgs
manual.

What do you think?

Thanks,
Ludo’.

[0] http://modules.sourceforge.net/