Realized this while debugging 804174. I propose to fix this by having the swarming recipe module add a named cache (vpython_envs) and an envvar to all triggered swarming tasks.
We'll probably should also scrape out all `~/.vpython-root` folders (they should all be small currently, can add a cleanup disk entry to nuke them).
Comment 1 by iannucci@chromium.org
, Feb 12 2018