curtin's tests assume `udevadm` is present on test systems

[Dan Watkins]

This is not the case in build chroots, so we see the following test failures during package build:

======================================================================
ERROR: test_start_clear_holders_deps (unittests.test_clear_holders.TestClearHolders)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/mock/mock.py", line 1305, in patched
    return func(*args, **keywargs)
  File "/<<PKGBUILDDIR>>/tests/unittests/test_clear_holders.py", line 712, in test_start_clear_holders_deps
    clear_holders.start_clear_holders_deps()
  File "/<<PKGBUILDDIR>>/curtin/block/clear_holders.py", line 690, in start_clear_holders_deps
    udev.udevadm_settle()
  File "/<<PKGBUILDDIR>>/curtin/log.py", line 88, in wrapper
    return log_call(func, *args, **kwargs)
  File "/<<PKGBUILDDIR>>/curtin/log.py", line 73, in log_call
    func, *args, **kwargs)
  File "/<<PKGBUILDDIR>>/curtin/log.py", line 79, in log_time
    return func(*args, **kwargs)
  File "/<<PKGBUILDDIR>>/curtin/udev.py", line 57, in udevadm_settle
    util.subp(settle_cmd)
  File "/<<PKGBUILDDIR>>/curtin/util.py", line 275, in subp
    return _subp(*args, **kwargs)
  File "/<<PKGBUILDDIR>>/curtin/util.py", line 129, in _subp
    raise ProcessExecutionError(cmd=args, reason=e)
ProcessExecutionError: Unexpected error while running command.
Command: ['udevadm', 'settle']
Exit code: -
Reason: [Errno 2] No such file or directory
Stdout: ''
Stderr: ''

======================================================================
ERROR: test that we skip zfs modprobe on unsupported platforms
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/mock/mock.py", line 1305, in patched
    return func(*args, **keywargs)
  File "/<<PKGBUILDDIR>>/tests/unittests/test_clear_holders.py", line 727, in test_start_clear_holders_deps_nozfs
    clear_holders.start_clear_holders_deps()
  File "/<<PKGBUILDDIR>>/curtin/block/clear_holders.py", line 690, in start_clear_holders_deps
    udev.udevadm_settle()
  File "/<<PKGBUILDDIR>>/curtin/log.py", line 88, in wrapper
    return log_call(func, *args, **kwargs)
  File "/<<PKGBUILDDIR>>/curtin/log.py", line 73, in log_call
    func, *args, **kwargs)
  File "/<<PKGBUILDDIR>>/curtin/log.py", line 79, in log_time
    return func(*args, **kwargs)
  File "/<<PKGBUILDDIR>>/curtin/udev.py", line 57, in udevadm_settle
    util.subp(settle_cmd)
  File "/<<PKGBUILDDIR>>/curtin/util.py", line 275, in subp
    return _subp(*args, **kwargs)
  File "/<<PKGBUILDDIR>>/curtin/util.py", line 129, in _subp
    raise ProcessExecutionError(cmd=args, reason=e)
ProcessExecutionError: Unexpected error while running command.
Command: ['udevadm', 'settle']
Exit code: -
Reason: [Errno 2] No such file or directory
Stdout: ''
Stderr: ''

(from https://jenkins.ubuntu.com/server/job/curtin-build/1204/console)

[Server Team CI bot (server-team-bot)]

This bug is fixed with commit f885a782 to curtin on branch master.
To view that commit see the following URL:
https://git.launchpad.net/curtin/commit/?id=f885a782

[Ryan Harper (raharper)]

This bug is believed to be fixed in curtin in version 20.1. If this is still a problem for you, please make a comment and set the state back to New

Thank you.