Upstream commit 7d463ddd0 adds lines like this (src/panels/information/informationpanelcontent.cpp around line 120 in the patch): + m_metaDataWidget->setDateFormat(static_cast<Baloo::DateFormats>(InformationPanelSettings::dateFormat())); Unfortunately that (and similar baloo-depending lines added in the commit) isn't ifdefed on baloo actually being a dep and of course fails without it, thus failing the build with USE=-semantic-desktop. With that commit patch-reversed, dolphin builds successfully (as of current head 90e1cc9c0).
Fixed in: https://cgit.kde.org/dolphin.git/commit/?id=2912894d4f13907bb05be0a2a0d4e432668d9817