That patch seems to be our best candidate so far, but the intermittent
nature of the failures make it hard to pin down... I don't see anything
obviously wrong with the patch, maybe some linux-user experts have a
better idea?
FWIW, I tried reproducing the issue on some local systems (no luck),
and on code pushed out to gitlab (where it works most of the time, and
the user builds where it fails are unpredictable.)
I fear the best we can do right now is stare at the code and try to
figure out what might be wrong :(