processargs exception print is not very useful

[bdkearns]

antlr4 build fails with simply "1.6" printed to console when Java 1.6 isn't present. str(e) just prints the exception args, which in this KeyError case is "1.6", not even really an indication of an error. I'd suggest replacing "print e" with "traceback.print_exc()".

also, this code is idented with tabs. i would have done a pull request but my editor isn't set up to use tabs in python code, and i think you'll find most others expect python indentation with spaces also.

http://legacy.python.org/dev/peps/pep-0008/#tabs-or-spaces

[parrt]

Hi. Thanks. Yeah,I've been meaning to get back to this bild system. I started teaching again after two years and so I'm prepping like crazy. I hope to have more time in December.