Confirmed (on focal) that the open-iscsi PPA fixes the issue as expected.
The final console messages on a "real" iSCSI-booted VM are now:
[ OK ] Reached target Final Step.
[ OK ] Finished Power-Off.
[ OK ] Reached target Power-Off.
Logging out of session [sid: 1, target: iqn.2010-04.org.ipxe.dolphin:risso, portal: 10.0.0.6,3260]
Logout of [sid: 1, target: iqn.2010-04.org.ipxe.dolphin:risso, portal: 10.0.0.6,3260] successful.
[ 24.782589] reboot: Power down
Confirmed (on focal) that the open-iscsi PPA fixes the issue as expected.
The final console messages on a "real" iSCSI-booted VM are now:
[ OK ] Reached target Final Step. 04.org. ipxe.dolphin: risso, portal: 10.0.0.6,3260] 04.org. ipxe.dolphin: risso, portal: 10.0.0.6,3260] successful.
[ OK ] Finished Power-Off.
[ OK ] Reached target Power-Off.
Logging out of session [sid: 1, target: iqn.2010-
Logout of [sid: 1, target: iqn.2010-
[ 24.782589] reboot: Power down
i.e. no "failed with exit status 141" errors.
Thanks for fixing so quickly!