Gentoo's Bugzilla –
Attachment 472248 Details for
Bug 618082dev-qt/qtwebengine-5.7.1-r1 fails to build with GCC-7.1.0: error: ‘mojo::ScopedMessagePipeHandle {aka class mojo::ScopedHandleBase<mojo::MessagePipeHandle>}’ has no member named ‘Pass’ handle_ = other.handle_.Pass();