build of 'cairo' fails

[Steven Bellovin <smb%cs.columbia.edu@localhost>]

On 5.0_STABLE, with up-to-date pkgsrc HEAD, I get

Making all in src
/usr/bin/make  all-am
cd .. && /usr/bin/make  am--refresh
cd .. && /usr/bin/make  config.h
/bin/sh ./config.status --recheck
  CC     cairo-xlib-display.lo
In file included from cairo-xlib-xrender.h:45,
                 from cairo-xlib-xrender-private.h:53,
                 from cairo-xlib-private.h:41,
                 from cairo-xlib-display.c:38:
/usr/pkgsrc/graphics/cairo/work/.x11-buildlink/include/X11/extensions/Xrender.h:33:35:
 error: X11/extensions/render.h: No such file or directory
In file included from cairo-xlib-xrender.h:45,
                 from cairo-xlib-xrender-private.h:53,
                 from cairo-xlib-private.h:41,
                 from cairo-xlib-display.c:38:
/usr/pkgsrc/graphics/cairo/work/.x11-buildlink/include/X11/extensions/Xrender.h:47:
 error: expected specifier-qualifier-list before 'PictFormat'
/usr/pkgsrc/graphics/cairo/work/.x11-buildlink/include/X11/extensions/Xrender.h:69:
 error: expected specifier-qualifier-list before 'Picture'
/usr/pkgsrc/graphics/cairo/work/.x11-buildlink/include/X11/extensions/Xrender.h:100:
 error: expected specifier-qualifier-list before 'GlyphSet'
/usr/pkgsrc/graphics/cairo/work/.x11-buildlink/include/X11/extensions/Xrender.h:108:
 error: expected specifier-qualifier-list before 'GlyphSet'
/usr/pkgsrc/graphics/cairo/work/.x11-buildlink/include/X11/extensions/Xrender.h:116:
 error: expected specifier-qualifier-list before 'GlyphSet'
/usr/pkgsrc/graphics/cairo/work/.x11-buildlink/include/X11/extensions/Xrender.h:241:
 error: expected '=', ',', ';', 'asm' or '__attribute__' before 
'XRenderCreatePicture'

and many more (presumably cascade) errors.  I'm planning to install 5.1 very 
soon; will that help?

                --Steve Bellovin, http://www.cs.columbia.edu/~smb