aliBuild
===

aliBuild homepage at http://alisw.github.io/alibuild/

cc7-nix-alibuild
---

**DISCLAIMER**: this is not ALICE production way of doing things, nor a battle
tested setup. It's only purpose is to serve as demonstrator of various possible
techniques and to stress a few design points I think are important.

This is a docker container, based on Graeme's cc7-nix, which has three goals:

- Allow people to play with aliBuild.
- Show how you do a nix overlay to customise the official nix distribution to
  your needs (e.g. picking up a newer version of CMake).
- Show how aliBuild can be integrated with other packaging systems, so that we
  can have the best of multiple worlds: a battle stressed, mainstream, or simply
  third party package manager for the system configuration, an HEP / ALICE specific
  tool for the stuff we really care about. Cooperation over conquest! ;-)

Once someone with rights uploads it, you will be able to play with it via:

    docker run -it hepsoftwarefoundation/cc7-nix-alibuild
    # Open a new shell with the O2 system requirements available
    nix-shell -p alice.o2BuildEnv
    # Check the environment. Everything should be green in this setup
    alibuild/aliDoctor O2 --defaults o2 --architecture slc7_x86-64
    # Attempt at building O2. Notice it will not build Python and other system
    # stuff but it will build ROOT, GEANT4 and fastjet (even if they exists in
    # Nix) since we consider them as critical and do not allow system packages.
    alibuild/aliBuild build O2 --defaults o2 --architecture slc7_x86-64

Notice the architecture is not required in general, but again I did not have time
to debug the container provided by Graeme.