The current package is outdated for years. The most recent usable version (through Portage) would be 8.4.12 but both of these versions will only support Drupal up until 7.x (EOL soon) while any newer version would require a full rewrite of the Ebuild as it is supposed to be installed with Composer now. Otherwise it should be replaced by Drush Launcher, which is a wrapper for the Composer driven version to be executed from CLI. These design choices by upsteam are questionable but in any case the current Ebuild is obsolete and does not provide any use. Reproducible: Always
