Jobs setting up more than 1 image fails with ValueError: invalid literal for int() with base 10: ''

Happening since the devstack patch https://review.opendev.org/c/openstack/devstack/+/886795 merged.

Fails as below:-
2023-07-19 01:12:44.183383 | controller | +++ lib/tempest:configure_tempest:301 : image_size_in_gib
2023-07-19 01:12:44.186369 | controller | +++ lib/tempest:image_size_in_gib:119 : local size
2023-07-19 01:12:44.190924 | controller | ++++ lib/tempest:image_size_in_gib:120 : oscwrap --os-cloud devstack-admin image show -c size -f value
2023-07-19 01:12:45.055357 | controller | usage: openstack image show [-h] [-f {json,shell,table,value,yaml}]
2023-07-19 01:12:45.055438 | controller | [-c COLUMN] [--noindent] [--prefix PREFIX]
2023-07-19 01:12:45.055450 | controller | [--max-width <integer>] [--fit-width]
2023-07-19 01:12:45.055460 | controller | [--print-empty] [--human-readable]
2023-07-19 01:12:45.055469 | controller | <image>
2023-07-19 01:12:45.055479 | controller | openstack image show: error: the following arguments are required: <image>
2023-07-19 01:12:45.170317 | controller | ++++ functions-common:oscwrap:2427 : return 2
2023-07-19 01:12:45.174387 | controller | +++ lib/tempest:image_size_in_gib:120 : size=
2023-07-19 01:12:45.178301 | controller | +++ lib/tempest:image_size_in_gib:121 : echo
2023-07-19 01:12:45.178524 | controller | +++ lib/tempest:image_size_in_gib:121 : python3 -c 'import math; print(int(math.ceil(float(int(input()) / 1024.0 ** 3))))'
2023-07-19 01:12:45.197214 | controller | Traceback (most recent call last):
2023-07-19 01:12:45.197249 | controller | File "<string>", line 1, in <module>
2023-07-19 01:12:45.197343 | controller | ValueError: invalid literal for int() with base 10: ''
2023-07-19 01:12:45.205412 | controller | ++ lib/tempest:configure_tempest:301 : disk=
2023-07-19 01:12:45.209824 | controller | + lib/tempest:configure_tempest:1 : exit_trap
2023-07-19 01:12:45.213259 | controller | + ./stack.sh:exit_trap:547 : local r=1
2023-07-19 01:12:45.218464 | controller | ++ ./stack.sh:exit_trap:548 : jobs -p
2023-07-19 01:12:45.224425 | controller | + ./stack.sh:exit_trap:548 : jobs=
2023-07-19 01:12:45.227487 | controller | + ./stack.sh:exit_trap:551 : [[ -n '' ]]
2023-07-19 01:12:45.232326 | controller | + ./stack.sh:exit_trap:557 : '[' -f /tmp/tmp.phuFS9io2I ']'
2023-07-19 01:12:45.236057 | controller | + ./stack.sh:exit_trap:558 : rm /tmp/tmp.phuFS9io2I
2023-07-19 01:12:45.241367 | controller | + ./stack.sh:exit_trap:562 : kill_spinner
2023-07-19 01:12:45.245280 | controller | + ./stack.sh:kill_spinner:457 : '[' '!' -z '' ']'
2023-07-19 01:12:45.249184 | controller | + ./stack.sh:exit_trap:564 : [[ 1 -ne 0 ]]
2023-07-19 01:12:45.254924 | controller | + ./stack.sh:exit_trap:565 : echo 'Error on exit'
2023-07-19 01:12:45.254945 | controller | Error on exit
2023-07-19 01:12:45.258724 | controller | + ./stack.sh:exit_trap:567 : type -p generate-subunit
2023-07-19 01:12:45.261436 | controller | + ./stack.sh:exit_trap:568 : generate-subunit 1689727847 1318 fail
2023-07-19 01:12:45.402879 | controller | + ./stack.sh:exit_trap:570 : [[ -z /opt/stack/logs ]]
2023-07-19 01:12:45.406897 | controller | + ./stack.sh:exit_trap:573 : /usr/bin/python3.10 /opt/stack/devstack/tools/worlddump.py -d /opt/stack/logs
2023-07-19 01:12:45.440788 | controller | Traceback (most recent call last):
2023-07-19 01:12:45.440856 | controller | File "/opt/stack/devstack/tools/worlddump.py", line 271, in <module>
2023-07-19 01:12:45.440891 | controller | sys.exit(main())
2023-07-19 01:12:45.440911 | controller | File "/opt/stack/devstack/tools/worlddump.py", line 248, in main
2023-07-19 01:12:45.440933 | controller | with io.open(fname, 'w') as f:
2023-07-19 01:12:45.440958 | controller | PermissionError: [Errno 13] Permission denied: '/opt/stack/logs/worlddump-2023-07-19-011245.txt'
2023-07-19 01:12:45.447843 | controller | *** FINISHED ***
2023-07-19 01:12:46.151871 | controller | ERROR

Example failure:-
https://e6631573c9d13b55a73e-3868013975e8773906368e2a701847c4.ssl.cf2.rackcdn.com/883988/24/check/neutron-tempest-plugin-designate-scenario/10ebd49/job-output.txt