Gentoo's Bugzilla –
Attachment 594698 Details for
Bug 699054net-libs/webkit-gtk-2.24.4 with media-libs/mesa-19.2.2[libglvnd] and media-libs/libglvnd-1.2.0-r1 - .../Source/WebKit/UIProcess/gtk/WaylandCompositor.cpp:134:116: error: ‘EGL_WAYLAND_BUFFER_WL’ was not declared in this scope