Updating debian apt
GPG error: Release: The following signatures were invalid: KEYEXPIRED 1409325681 KEYEXPIRED 1409325681 KEYEXPIRED 1409325681 KEYEXPIRED 1409325681 W: Failed to fetch W: Some index files failed to download. apt-get is the command-line tool for handling packages, and may be considered the user's "back-end" to other tools using the APT library.Unless the issue is already known/documented, it should be reported so it can be further investigated.
However, Qubes has been working closely with the Whonix project which is based on Debian.
Similarly a plus sign ( ) can be used to designate a package to install.
These latter features may be used to override decisions made by apt-get's conflict resolution system.
This enables exact matching of the source package name and version, implicitly enabling the APT:: Get:: Only-Source option.
Like clean, autoclean clears out the local repository of retrieved package files.