Knowledge Base:Unmasking a package

Synopsis
Some software packages are masked so that users can be properly warned before installing them. Any attempt to install such a package results in the warning from Portage that additional changes are needed before it will proceed:

Environment
Any Gentoo installation.

Analysis
Next to the KEYWORDS settings in the ebuild, additional masking is available within Gentoo. Developers can explicitly mask out a package by mentioning it in the file within the profiles. The masked file can be coupled with an explanation as to why the package has been masked. Common reasons for masking include pre-release (unstable) versions of a certain package, there is no more upstream development, and there are known security issues in the package.

Using
Re-running the emerge command with  automatically queues the required text file alteration:

As with all configuration files, the final update is made by running dispatch-conf (or alternatively etc-update):

Examine the diff output of the configuration files, press to exit the pager (if no commands appear at the end), and then  for use-new to accept the alterations. Press to zap (disregard) the changes.

Finally, re-run emerge one last time:

Using traditional files
Create the directory if it does not yet exist:

Add the required line to a (new) file:

Using directories
Create the directory if it does not yet exist:

Create a file (or files) for the unmask operations to perform. For instance, to unmask the  package as mentioned earlier, run:

Most masked packages will not accept generic keywords, so specific keywords may need granted for the masked package.