So the hang is just specific to purging, lowering importance. However,
this still looks a bit worrying:
[7.142392] cloud-init[787]: Command: ['initctl', 'emit', 'cloud-config',
'CLOUD_CFG=/var/lib/cloud/instance/cloud-config.txt']
[7.143936] cloud-init[787]: Exit code: 1
[7.145140]
Ah, I know now. cloud-init's prerm stops cloud-init-local.service, so if
you are trying to purge cloud-init from user-data, stopping this will
kill apt/dpkg/etc. I'll work around that in autopkgtest, but I wonder if
we want to support that case in cloud-init itself. I'll have a closer
look and
