Currently we use set -o verbose which runs before variable expansion so it prints out lines like this which don't include the value of $extra_args:

PATH=$PATH:/data/multiversion MONGOD_UNITTEST_RLP_LANGUAGE_TEST_BTROOT=/opt/basis python buildscripts/resmoke.py --suites=multiversion $extra_args --log=buildlogger

We should probably use set -o xtrace instead of or in addition to verbose.