[Clas12_software] geant4 common environment

[Maurizio Ungaro]

In the long run, we need to keep track of the version of software and library dependencies, including gemc, geant4, qt, etc.

To accomplish this, we can use a new environment variable, JLAB_VERSION. 

The new environment can be set like this:

setenv JLAB_ROOT /site/12gev_phys
setenv JLAB_VERSION production
source $JLAB_ROOT/ce/releases/$JLAB_VERSION/jlab.csh

A list of version will be kept here:

https://gemc.jlab.org/gemc/Documentation/Entries/2014/2/27_jlab_versions.html

This should allow seamless access to previous version of software. 
The step-by-step instructions on how to install gemc has been updated accordingly.

Let  Zhiwen or me know if you have any questions, suggestions, etc.

Regards,

Maurizio


PS: there's a Q&A on gemc at 2pm today in F113.