How to update Gentoo's profile

In Gentoo Linux, the profile dictates system settings that define how packages are compiled and managed. It includes architecture-specific options, USE flags, and package masks. These settings control the system's behavior during software installation and updates. Keeping the profile updated is necessary to ensure compatibility with new packages and system configurations.

Profiles are structured hierarchically, and they align with different system types, like desktop or server environments. A profile may also include security features or optimizations for specific hardware architectures. Gentoo profiles are updated regularly, and using an outdated profile can cause issues such as build failures or incompatibility with newer software.

Switching or updating to a new profile is a standard maintenance task. It involves selecting a new profile that fits the current system needs and rebuilding packages to match the new settings. A correct profile update ensures the system remains compatible and optimized with the latest software in the Gentoo repositories.

1. Check the current profile.

   $ sudo eselect profile list
   Available profile symlink targets:
     [1]   default/linux/amd64/17.1 (stable) *
     [2]   default/linux/amd64/17.1/desktop (stable)
     [3]   default/linux/amd64/17.1/desktop/plasma (stable)
     [4]   default/linux/amd64/17.1/hardened (stable)

   This shows the currently active profile marked with a * and available profiles. Choose a profile that fits your system's role (desktop, server, etc.).

2. Select a new profile.

   $ sudo eselect profile set <profile_number>
   $ sudo eselect profile set 2

   Replace <profile_number> with the appropriate number from the list.

3. Sync the portage tree.

   $ sudo emerge --sync
   >>> Syncing repository 'gentoo' into '/usr/portage'...
   >>> Repository sync in progress...
   >>> Sync finished.

   This updates the package repository to ensure you have the latest packages and profile settings.

4. Rebuild packages.

   $ sudo emerge -uDN @world
   >>> Calculating dependencies... done!
   >>> Emerging (1 of 10) sys-libs/glibc-2.32-r1
   >>> Emerging (2 of 10) app-editors/vim-8.2.0000
   >>> Emerging (10 of 10) dev-lang/python-3.8.2-r1

   This command ensures that all packages align with the new profile settings.

5. Clean unused packages.

   $ sudo emerge --depclean
   >>> Removing outdated packages...
   >>> Packages cleaned successfully.

6. Verify profile update.

   $ sudo emerge --info
   Portage 3.0.18 (default/linux/amd64/17.1/desktop, gcc-10.2.0, glibc-2.32-r1, 5.4.80-gentoo x86_64)
   System settings:
   USE="X alsa cups gtk kde qt5"

   Check the output to confirm that the new profile has been successfully applied.