Comment 12 for bug 1851250

Here I am, trying to use headless Chromium to render screenshots, and on
Ubuntu 20.04, I find that Chromium is simply not writing to `/tmp`. So,
let me add my voice to the chorus of those flummoxed and frustrated by
this decision.

The easiest way to get around this appears to be to install Chromium
from an unofficial PPA. Ironic, given the intent of "improved security".
As they say, security at the expense of usability comes at the expense
of security.