Also in the last time I'm seeing often on an "apt-get dist-upgrade" this:
W: Can't drop privileges for downloading as file '/var/cache/apt/archives/partial/libpython3.5_3.5.1-6ubuntu2_amd64.deb' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied)
Also in the last time I'm seeing often on an "apt-get dist-upgrade" this:
W: Can't drop privileges for downloading as file '/var/cache/ apt/archives/ partial/ libpython3. 5_3.5.1- 6ubuntu2_ amd64.deb' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied)
The permissions of the directory are this:
root@ubuntu:~# stat /var/cache/ apt/archives/ partial | grep 'Access: ('
Access: (0700/drwx------) Uid: ( 113/ _apt) Gid: ( 0/ root)