Switch to rereading the partition table and checking
We still may race and need more than one reread of the partition table.
Drop using util.wait_for_removal and instead loop, sleep while triggering
partition table rereads until the partitions are cleared.
clear-holders: wait for partition removal when wiping disks with partitions
When wiping a disk with partitions curtin races the kernel in removing
sysfs entries for the partitions. This shows up as a OSError when
asserting the disk is clear as partition sysfs paths are unexpectidly gone
during the building of the holder tree.
To prevent the race, wipe_superblock will check if the device has partitions
and if so after wiping the the superblock, rescan the device partition table
and then use util.wait_for_removal for each of the partition sysfs paths.
This ensures that after wiping the disk, none of the partition sysfs paths
are still present.
vmtest: Skip proposed pocket on dev release when 'proposed' in ADD_REPOS.
The -proposed pocket for an Ubuntu development release is somewhat
expected to be broken. So, when testing proposed with via setting
CURTIN_VMTEST_ADD_REPOS=proposed, this will skip adding the repo for
the development release.
It allows testing of development release with:
CURTIN_VMTEST_ADD_REPOS=PROPOSED
