Cindy-Sue, your caution appreciated, but I too am in the habit of deleting lock files. But in this case, it did not help. I also adventurously gave the partial directory 755 permissions rather than 700, but still no go.
In my ignorance, what strikes me as a problem is that there is no "_apt" in /etc/group. Googling suggests that _apt should be a named user, but can get wiped out. In discussion of Bug#806406: 1.1 regression: apt-get hangs forever, due to missing "_apt" user Bug#812251: apt: suddenly segfaults after "apt update" I get impression that _apt, the owner of /var/lib/apt/partial/ is a dynamic system user. Using a static user like sys or daemon is not a good idea. It seems that something that copies /etc/passwd can clobber _apt. Do dynamic system users appear in /etc/group? I do # cat /etc/passwd | grep apt _apt:x:116:65534::/nonexistent:/bin/false I get the impression this is normal, but shouldn't _apt be in /etc/group file as user? When debian packages are built for experimental, it seems this is needed: # adduser --force-badname --system -home /var/empty --no-create-home \ --quiet _apt wouldn't this put _apt into /etc/group? I'm really nervous about issuing this command without any idea of what I'm doing. Haines
