This package uses a deprecated Go eclass. It must be migrated to go-module.eclass. Fixing this does not require a revbump as it'll already be successfully installed. $ pkgcheck scan -k DeprecatedEclass dev-embedded/arduino-builder dev-embedded/arduino-builder DeprecatedEclass: version 1.3.25: uses deprecated eclass: golang-build (migrate to go-module.eclass) DeprecatedEclass: version 1.3.25: uses deprecated eclass: golang-vcs-snapshot (migrate to go-module.eclass) DeprecatedEclass: version 1.4.1-r1: uses deprecated eclass: golang-build (migrate to go-module.eclass) DeprecatedEclass: version 1.4.1-r1: uses deprecated eclass: golang-vcs-snapshot (migrate to go-module.eclass)
It looks like this applied to an older version of the ebuild which is no longer in the tree.