Phase 1 silently aborted right after the 'cuda-drivers candidate' step
— before snapshotting, stopping containers, installing the new driver,
or rebooting. Symptom: phase2 showed driver still at 570.124.06 and
containers with multi-hour uptimes (proof they were never stopped).
Cause: `apt-cache policy cuda-drivers | head -10`. head reads its 10
lines and closes the pipe early; that delivers SIGPIPE to apt-cache,
which under `set -o pipefail` propagates as a non-zero exit, and
`set -e` immediately terminates the remote shell. The same hazard
existed in phase2's `docker ps ... | head -15`.
Fix is one-line per call site: drop the head. apt-cache policy output
for cuda-drivers is short (~10 lines), and docker ps's container list
on irv-ml1 is small enough to print fully.
vh
c9c4262bdb