[cairo] What does it take to get a make check to pass with the xcb target, using CAIRO_REF_DIR?

[darxus at chaosreigns.com]

It looks like almost all of the xlib errors are: "Error: Created surface has content 0" - no output file.

And almost all of the xcb failures are "Error: Created an error surface: invalid value for an input cairo_format_t".

What's causing these?  Am I correct in believing all of these tests should
pass, since I'm generating my own CAIRO_REF_DIR, and not making any
changes?

darxus at dancer:~/source/cairo-ref.xlib.xvfb.3$ cat *.log | grep Error | sort | uniq -c | sort -nr 
    528 Error: Created surface has content 0 (expected 4096)
      5 Error: Failed to set xlib-window target
      5 Error: Failed to set xlib-fallback target
      4 Error: Function under test failed

darxus at dancer:~/source/cairo-ref.xcb.xvfb.2$ cat *.log | grep Error | sort | uniq -c | sort -nr 
   1584 Error: Created an error surface: invalid value for an input cairo_format_t
      5 Error: Failed to set xcb-window& target
      5 Error: Failed to set xcb-window target
      5 Error: Failed to set xcb-fallback target
      4 Error: Function under test failed