Don't try to take screenshot when VM does not have vga device

[dustymabe]

For arm when oz tries to take a screenshot of a failed install it fails because there is no vga console on arm and thus we get the error: libvirtError: internal error: unable to execute QEMU command 'screendump': There is no QemuConsole I can screendump from.

Should we attempt to detect if the libvirt xml has a vga device before attempting to grab the screenshot?

Here is the full log for a run where this happened:
https://kojipkgs.fedoraproject.org//work/tasks/2710/17022710/oz-armhfp.log

[clalancette]

Sorry I've taken so long to get to this. Life, you know ;).

Anyway, I see your point; if there is no valid screen setup, we should skip the dump and get the original stacktrace instead. I've just pushed a commit which should fix this problem; check it out and let me know if it does.

Thanks for the bug report!

[dustymabe]

Sorry I've taken so long to get to this. Life, you know ;).

indeed! I know all too well!

Anyway, I see your point; if there is no valid screen setup, we should skip the dump and get the original stacktrace instead. I've just pushed a commit which should fix this problem; check it out and let me know if it does.

Thanks for the bug report!

No problem. Thank you! For everyone else following along, this should be fixed in 5eed862