Situation
See the attached image: the icon for the Firefox window has disappeared after an interrupted upgrade (VM crashed), but the icons on the desktop and in the start menu are fine. (I'm using Lubuntu 20.04 with LXQt DE if that matters.)
What I did so far
I have tried various ways of fixing the interrupted upgrade, which seem to have done their job well (i.e. finished successfully, no error messages), including removing/reinstalling Firefox, but that apparently did not help.
From bash-history:
pkg --configure -a apt-get install -f apt autoremove apt-get update --fix-missing dpkg-reconfigure -a dpkg --configure -a apt-get clean apt-get -f install apt-get update apt-get upgrade apt install --reinstall firefox dpkg -P firefox apt install firefox Question
How can I debug this problem? In other words, while a command that restores the icon would also be nice, I would like to get a deeper understanding of what went wrong and how it is being fixed.
I.e.:
- where is the Firefox window icon supposed to come from?
- how can I check if it is there? (I mean maybe it is not necessarily a stand-alone file, but a resource built into the executable or something similar. In that case, how can I check if that resource is there?)
- how can I find out which package is broken?
- how can I find out that no other packages are broken, due to the interrupted upgrade? (the commands I ran above supposedly fixed the system, but apparently this is not the case, at least for Firefox -- maybe other packages are still broken in subtle ways)
Remark
I have another VM with the same OS/DE, also upgraded recently (with success), where the window icon is fine. In other words, I assume that it is not a bug in the package.
