I've gotten pipe_tasks and pex_config to pass py2 Jenkins by making a tickets/
DM-7292 branch for pex_config and editing pex_config/listField per Tim Jenness' suggestion. However, the full build I ran failed on obs_subaru. Something I didn't touch, pex_config/dictField, is apparently causing a FieldValidationError when obs_subaru is tested. I can't tell if this problem arose indirectly from my small edit to pex_config/listField or not? It's strings all the way down. Here is the relevant Jenkins brain dump. Input appreciated.