Built piglit from svn on Ubuntu MATE 16.04 ppc. Already the sanity test fails,
specifically:
root@T800:~/build/piglit# /root/build/piglit/bin/gl-1.0-readpixsanity -auto
-fbo
    RGB(A) worst-case error was 6.641274 bits at (32, 80)
        expected (0.840188, 0.394383, 0.783099, 0.798440)
        got (0.799995, 0.784309, 0.396076, 0.839211)
    Depth worst-case error was 23.862089 bits at (107, 6)
        expected 0.911647; got 0.002813.
    Stencil failed at (0, 1).
        Expected 255; got 233.
PIGLIT: {"result": "fail" }

But I must admit that I've no experience with piglit, built and used it for the
first time.