Oh! That works. So I just commented out the entire export LD_LIBRARY_PATH from my bashrc file. Not sure why I had it in there (maybe for some other program? will have to see what breaks).
Okay, so when LD_LIBRARY_PATH = "" , and I type in julia, what version of libstdc++ does it use? Does it use the system one (unlikely since the minimum version is only 3.4.19) or does it use the one that itself shipped with? I am guessing the latter.
And ofcourse, other programs that use libstdc++ use the system one… since how would they be aware of the Julia one (unless I append it to LD_LIBRARY_PATH which I was doing and it was messing things up).
Ah, 30 minutes to learn linux… a lifetime to master.