Ever wondered if enabled gentoo overlay is used at all on a gentoo machine? To list installed and overlays use the eselect command:

Additional gentoo overlays have a URL listed. The sandbox overlay is a local overlay local overlay, and is not taken into count. The index f.e. like [42] differs between gentoo hosts, this is normal, it is not globally significant. Use the eix to get a overview which software is installed from a overlay:

This is a example output, notice gentoo overlay is left out, it is basically portage:

eix --installed-in-overlay
[I] app-misc/doublecmd-bin [1]
     Available versions:  (~)1.0.1 (~)1.0.2 (~)1.0.4{tbz2} {gtk qt5}
     Installed versions:  1.0.4{tbz2}(18:06:08 02/03/22)(gtk -qt5)
     Homepage:            https://doublecmd.sourceforge.io/
     Description:         Free cross platform open source file manager with two panels side by side.

[I] games-roguelike/cataclysm-dda [2]
     Available versions:  (~)0.9f{tbz2} **9999-r9*l {astyle clang debug lintjson lto ncurses nls pch sdl sound test xdg KERNEL="Darwin linux"}
     Installed versions:  0.9f{tbz2}(22:15:11 02/02/22)(ncurses nls sdl sound -astyle -clang -debug -lintjson -lto -pch -test -xdg KERNEL="linux -Darwin")
     Homepage:            https://cataclysmdda.org
     Description:         Roguelike set in a post-apocalyptic world

[1] "guru" /var/db/repos/guru
[2] "raiagent" /var/db/repos/raiagent

Found 2 matches

In the output above 2 overlays are installed. The GURU overlay and the raiagent overlay are installed and enabled in the example. The result is, no wasted resources at this gentoo node. The sandbox overlay is a local repository,hence the name, sandbox.