Now it is enabled only for these platforms: - platform: EFL/GTK/Darwin and architecture: X86_64/Aarch64 - platform: iOS and aarchitecture: ARM-Thumb2 I tried to enable it on ARM-Thumb2 Linux, WebKitEFL built fine, but CSS tests crash. Alex mentioned on webkit-dev that the ABI is different on iOS, so it might be responsible for crashes - https://lists.webkit.org/pipermail/webkit-dev/2014-June/026611.html I don't have time right now, but I'm going to work on it in the near future. (in 1-2 months) If somebody else have more time now, feel free to pick it up, but please add a comment to the bug.