As in summary: the script downloads the file at <http://sources.gentoo.org/cgi-bin/viewvc.cgi/gentoo-x86/app-admin/hddtemp/files/hddgentoo.db>, which is outdated and does not contain the drives added in the latest bugs. It should probably be updated to download from gitweb.gentoo.org.
Created attachment 440436 [details, diff] hddtemp-fix-588666-574090.patch Quick and dirty patch to fix current bug, also fixes bug #574090 and removes old.
Created attachment 440438 [details, diff] hddtemp-fix-588666-574090.patch Oops, wrong patch version. Current one is right.
Would you rather have a github PR?
Thanks! Fixed. There was no need to have a second version of this script as update-hddtemp.db-1 and therefore there was no need to update ebuild, just bump to force update for users.