apt: retry acquire the cache if it is already locked for 120s
An idea that was in the back of my head for some time and that I would love to get feedback on (branch just a RFC to demo the idea):
$ sudo apt full-upgrade
Cache locked by another package manager, retrying... 1%
...
And it either fails after a timeout (120s right now) or continue once the cache can be locked. WDYT?