I tried running the script against our oldest and largest git repo (53k commits over ~7 years) and it crashed.

Unfortunately the only output I've still got from the run is

-- Done extracting changes... Now estimating partial correlations on these files...
Loading required package: methods
Error in asMethod(object) :
  Cholmod error 'problem too large' at file ../Core/cholmod_dense.c, line 105

Not sure if it's useful but I'm on yosemite with R version 3.1.2 (2014-10-31) -- "Pumpkin Helmet"