So in AL9, we get a warning from gzip about the GZIP=-n in the environment:

gzip: warning: GZIP environment variable is deprecated; use an alias or script

when we are making a tarfile with tardir:, of course we do this to get a compressed
file that is repeatable; but we should instead probably
a) switch to bz2 and
b) possibly switch to using the python tar module to make the tarfile, but that will involve
walking the directory tree, handling the exclude list, etc.