This is the only thing that works for what I needed to accomplish (creating a virtual environment then activating it, then installing requirements from a bash script):
spawn a subshell / child shell from the script, as in:
stupid_file.sh
( set -o errexit #bunch of commands #one line fails ) run the stupid_file using:
source stupid_file.sh <file arguments here> || true THE END.
** takes a bow **
(credit goes to the above two postersJeff and Terdon)