Iguana

[dglazier]

Include an Iguana interface for clas12root
Header only classes given in iguana/ loaded at runtime via LoadIguana.C
Simple usage, configuration done behind the scenes :

  clas12root::Iguana ig;
  ig.GetTransformers().Use("clas12::MomentumCorrection");
  //add many other transforms, creators, filters
  ...
  while ( chain.Next() ){
    ...
    //apply all corrections to particles
    ig.GetTransformers().doAllCorrections({electron,pip,pim},{&p4el,&p4pip,&p4pim});

[c-dilks]

If this is all $IGUANA is used for, then I don't think it's necessary, since $ROOT_INCLUDE_PATH and $(DY)LD_LIBRARY_PATH should be sufficient. Have you tested that?

[dglazier]

You are correct, in principle includes and lib directories can be linked in that way. However I do have a preference for the explicit setting of the variable for a couple fo reasons. I think it is simpler and clearer for inexperienced users installing on their own machines and when there are multiple versions of dependencies on a machine (in this case iguana) you can easily switch between them and know exactly which one you are using. For example on ifarm at the moment when I was trying to just use ROOT_INCLUDE_PATH for linking clas12root there turned out to be an issue that module unload did not remove clas12root from the ROOT_INCLUDE_PATH and I got strange and difficult to debug errors.

I do not have particularly strong opinion on this, so could be persuaded to change.
Cheers
Derek

[c-dilks]

This PR is associated with the following upstream PRs:

• feat: add ROOT macro example iguana#210
• iguana: add environment variables for ROOT and clas12root support clas12-env#11

[baltzell]

Can you provide an example of how to reproduce the problem with a (clas12root) module not unloading correctly? I currently can't reproduce it.

[baltzell]

FWIW, ROOT_INCLUDE_PATH is necessary to make clas12root (and clas12-elSpectro) movable

[dglazier]

Actually, no I cannot reproduce this, clas12root is removed from ROOT_INCLUDE_PATH.