Gentoo's Bugzilla –
Attachment 533524 Details for
Bug 656684net-analyzer/wireshark-2.6.1[qt5] with dev-qt/*-5.11.0_rc2 - .../work/wireshark-2.6.1/ui/qt/packet_format_group_box.cpp:21:18: error: aggregate ‘QStyleOption style_opt’ has incomplete type and cannot be defined