There appears to be a problem with how parsing is handled for revision-info.
On line 105 and 106 has
String infos = stdout.toString().split("
rev = infos;
With a "young" branch revision-info is returning
But the parsing doesn't seem to be working correctly due to the two space chars at the beginning of the line. Either the result of revision-info should be chomped or a fancier regex that handles multiple white-space correctly needs to be used.