I'm trying to remove X11 dependencies from my system.
src/renderer-backend-egl.c includes /usr/include/EGL/eglplatform.h and it tries to include <X11/Xlib.h>.
What I suppose:
1. gui-libs/libwpe should have USE flag X and wayland
2. gui-libs/libwpe should depend on media-libs/mesa[egl,X?,wayland?]
3. WL_EGL_PLATFORM needs to be defined somewhere for gui-libs/libwpe[wayland]