Error encountered during
apt install indicated that the file couldn't be accessed by user
When installing package from local file (
.deb file), following error might be occurred.
Processing triggers for dbus (1.14.0-2ubuntu3) ... N: Download is performed unsandboxed as root as file 'full_path_of_deb_file_name' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied)
Usually apt tries to run the process that fetches packages as a different user called
_apt to increase security. That's no problem if it has to download packages from the internet. But if you tell it to install a
.deb file that's already on your system, it needs to have permission to access that file by
_apt user. Otherwise, above error will be shown.