This tutorial will help you to install deb files on Ubuntu and other Debian-based systems. Another apt command is a powerful command-line tool, which works with Ubuntu’s Advanced Packaging Tool, and helps in managing Debian packages. Instead of fiddling with the command-line.The Ubuntu and other Debian based systems provides dpkg (Debian Package Management System) for directly installing. That way I can easily uninstall them using Ubuntu Software. Personally I prefer to use the first solution, and just download my deb files under Downloads/deb for example. For example, you need to make sure the ~/tmp files get deleted on reboot.

You could set this in your bash if you wanted to, but I'm not sure of the ramifications of moving /tmp files. This only sets TMPDIR in firefox, so other programs will continue to use the canonical location of /tmp. With this, opening a deb file via Ubuntu Software will now work as intended. firefox & is invoking firefox in the background. TMPDIR='~/tmp' is setting the TMPDIR env variable to a folder in home folder. issue a command TMPDIR='~/tmp' firefox &.create a folder in your home directory, eg ~/tmp.The easy solution like others have mentioned is just save it Downloads and then install using Software Install.Just moved to Ubuntu and I've also been bitten by this. The same can be done within Nautilus by right-clicking and opening Properties for a /tmp/.deb file and switching the Open with from current default Software Install to the other suggestion. You can verify that it is gnome-software in Preferences->Applications: This second one is the gnome-software association. When choosing application to open change for the suggested or default Software Install to the other further down the list. You can install gdebi or similar software as suggested in other answers but there is a workaround to modify the file association to use the other Software Install which is associated with gnome-software: Firefox

The snap-store command will error with Failed to install file: not supported Workarounds Snap-store -local-filename '/tmp/mozilla_user0/app_b' Can be easily verified by running these commands: gnome-software -local-filename '/tmp/mozilla_user0/app_b' This snap app software centre has the problem installing local files from the /tmp directory. Ubuntu 20.04 has two 'Software Install' applications, one is gnome-software and the other is snap-store, installed by Canonical via snap.

Installing deb file