fwupdmgr get-updates hangs if run before fwupdmgr refresh

[zaz]

Qubes OS release

Qubes OS 4.2

Brief summary

Running qubes-fwupdmgr get-updates hangs if you run it before qubes-fwupdmgr refresh.

Steps to reproduce

1. Fresh install on a StarLabs StarBook Ultra
2. sudo qubes-fwupdmgr get-updates
3. Wait

Expected behavior

Either show updates or show an error stating that qubes-fwupdmgr refresh must be run first.

Better yet, check not only if qubes-fwupdmgr refresh has been run, but when it has last been run, and show a warning if it is old (to avoid a user falsely thinking there are no new updates without realizing they need to refresh before running get-updates).

Actual behavior

qubes-fwupdmgr hangs. When terminated with Ctrl + C, outputs the following:

$ sudo qubes-fwupdmgr get-updates
^CTraceback (most recent call last):
  File "/usr/sbin/qubes-fwupdmgr", line 731, in <module>
    main()
  File "/usr/sbin/qubes-fwupdmgr", line 709, in main
    q.get_updates_qubes()
  File "/usr/sbin/qubes-fwupdmgr", line 586, in get_updates_qubes
    self._get_dom0_updates()
  File "/usr/sbin/qubes-fwupdmgr", line 196, in _get_dom0_updates
    new_data = os.read(mstdout, 4096)
               ^^^^^^^^^^^^^^^^^^^^^^
KeyboardInterrupt

Additional information

After running qubes-fwupdmgr refresh, it works as expected:

$ sudo qubes-fwupdmgr get-updates
======================================================
Dom0 updates:
======================================================
No updates available.