grep -ri "dev-qt" /etc/portage

/etc/portage/package.unmask:# required by dev-qt/qtdbus-5.15.2::gentoo
/etc/portage/package.unmask:# required by dev-qt/qtgui-5.15.2-r1::gentoo[dbus]
/etc/portage/package.unmask:# required by dev-qt/qtprintsupport-5.15.2::gentoo
/etc/portage/package.unmask:=dev-qt/qtcore-5.15.2-r2
/etc/portage/package.unmask:# required by dev-qt/qtprintsupport-5.15.2::gentoo
/etc/portage/package.unmask:=dev-qt/qtwidgets-5.15.2
/etc/portage/package.unmask:=dev-qt/qtsvg-5.15.2
/etc/portage/package.unmask:=dev-qt/qtprintsupport-5.15.2
/etc/portage/package.unmask:# required by dev-qt/qtgui-5.15.2-r1::gentoo[dbus]
/etc/portage/package.unmask:# required by dev-qt/qtprintsupport-5.15.2::gentoo
/etc/portage/package.unmask:=dev-qt/qtdbus-5.15.2
/etc/portage/package.unmask:# required by dev-qt/qtwidgets-5.15.2::gentoo
/etc/portage/package.unmask:# required by dev-qt/qtprintsupport-5.15.2::gentoo
/etc/portage/package.unmask:=dev-qt/qtgui-5.15.2-r1
/etc/portage/package.use/zz-autounmask:# required by dev-qt/qtwebengine-5.15.1::gentoo
/etc/portage/package.use/zz-autounmask:# required by dev-qt/qtwidgets-5.15.2::gentoo[gtk]
/etc/portage/package.use/zz-autounmask:>=dev-qt/qtgui-5.15.2-r1 dbus jpeg
/etc/portage/package.use/zz-autounmask:>=dev-qt/qtcore-5.15.2-r2 icu
/etc/portage/package.use/zz-autounmask:>=dev-qt/qtmultimedia-5.15.2 widgets
/etc/portage/package.use/zz-autounmask:# required by dev-qt/qtwebengine-5.15.2_p20210224::gentoo
/etc/portage/package.use/zz-autounmask:>=dev-qt/qtwebchannel-5.15.2 qml
/etc/portage/package.use/zz-autounmask:# required by dev-qt/qtwebengine-5.15.2_p20210224::gentoo
/etc/portage/package.use/zz-autounmask:>=dev-qt/qtwebengine-5.15.2_p20210224 widgets
/etc/portage/package.use/zz-autounmask:# required by dev-qt/qtwayland-5.15.2-r1::gentoo
/etc/portage/package.use/zz-autounmask:# required by dev-qt/qtwayland (argument)
/etc/portage/package.use/zz-autounmask:>=dev-qt/qtgui-5.15.2-r1 egl
/etc/portage/package.use/xfce:# required by dev-qt/qtcore-5.15.1-r1::gentoo