Comment 3 for bug 960893

From config:
Clutter - 1.9.14 (snapshot)

 • Global:
        Prefix: /usr
        Libdir: ${prefix}/lib/arm-linux-gnueabihf
        Sysconfdir: /etc

 • Compiler options:
        Clutter debug level: yes
        Compiler flags: -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Wformat-security -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Wformat-security -Werror=format-security -Wall -g
        Profiling enabled: no
        Enable coverage tests: no
        Enable deprecated symbols: no

 • Documentation:
        Build API Reference: yes
        Build Additional Documentation: no (Generate PDF: no)

 • Extra:
        Build introspection data: yes
        Build conformance test suite: yes
        Build X11-specific tests: yes

 • Clutter Backends:
        Windowing systems: x11 egl (WARNING: Experimental backends enabled)
        Input backends: x11

     - X11 backend options:
        Enabled extensions: xext xfixes xdamage xcomposite xge xi xkb
        Build X11-specific tests: yes

It might be the case that it's using the egl windowing system while checking for x11, as in theory x11 should be supported just fine.