Comment 2 for bug 1577926

This bites me as well.

I tried symlinking /usr/bin/apt-key to /bin/true but that also fails.

Strace shows:

24419 execve("/usr/bin/apt-key", ["/usr/bin/apt-key", "--quiet", "--readonly", "verify", "--status-fd", "3", "/tmp/apt.sig.masxvS", "/tmp/apt.data.Orpf94"], [/* 25 vars */]) = -1 EPERM (Operation not permitted)
24419 write(2, "Couldn't execute /usr/bin/apt-key to check /var/lib/apt/lists/no.archive.ubuntu.com_ubuntu_dists_xenial_InRelease", 113) = 113
...
24418 write(2, "Sub-process apt-key returned an error code (111)", 48) = 48
24418 exit_group(111) = ?
...
24417 write(2, "gpgv exited with status 111\n", 28) = 28

So the finger pointing at gpgv seems to be in error.

Though running it with strace might change things as well.

Apparmor is running on the machine and is enforcing (as a default setting, I did nothing specific to either enable or disable anything in it, or even initiate installation or enforcement), but nothing is logged about apt-key.