MarsSeed [1] filed a deletion request for sem [2]: EOL alpha software from 2006. PKGBUILD likely broken since 2012-2013: ==> ERROR: sem is not available for the 'x86_64' architecture. ==> ERROR: license should be an array ==> ERROR: source should be an array ==> ERROR: url should not be an array [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/sem/