How do I update a single package? As far as
man apt-get says
apt-get upgrade doesn't take a package/list of packages as parameter:
upgrade is used to install the newest versions of all packages currently installed on the system from the sources enumerated in
/etc/apt/sources.list. Packages currently installed with new versions available are retrieved and upgraded; under no circumstances are currently installed packages removed, or packages not already installed retrieved and installed. New versions of currently installed packages that cannot be upgraded without changing the install status of another package will be left at their current version. An update must be performed first so that apt-get knows that new versions of packages are available.