anchor.diff:      "--enable-encoders"
       "--${boolEn (libdrm != null)}-drm"
       "--${boolEn (libx11 != null)}-x11"
  -    "--${boolEn (libx11 != null && mesa != null)}-glx"
  +    "--${boolEn opengl-dummy.glx}-glx"
       "--${boolEn (wayland != null)}-wayland"
  -    "--${boolEn (wayland != null && mesa != null)}-egl"
  +    "--${boolEn opengl-dummy.egl}-egl"
       "--disable-gtk-doc"
       "--disable-gtk-doc-html"
       "--disable-gtk-doc-pdf"
  
positive.code: , libx11
  , libxrandr
  , libxrender
  , mesa
  , renderproto
  , systemd_lib
  , wayland
  
negative.code:     libx11
      libxrandr
      libxrender
      opengl-dummy
      renderproto
      systemd_lib
      wayland
  