brew upgrade cairo (1.12.4) fails

brew --version

HOMEBREW_VERSION: 0.9.3
HEAD: fe737ea4b3d37f392bedf92510f4868a0675574f
HOMEBREW_PREFIX: /usr/local
HOMEBREW_CELLAR: /usr/local/Cellar
CPU: dual-core 64-bit core2
OS X: 10.6.8-i386
Xcode: 3.2.6
GCC-4.0: build 5494
GCC-4.2: build 5666
LLVM-GCC: build 2335
Clang: 1.7 build 77
X11:  => /usr/X11
System Ruby: 1.8.7-358
Perl: /usr/bin/perl
Python: /usr/bin/python
Ruby: /usr/bin/ruby => /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby

brew doctor

Warning: /Library/Frameworks/Mono.framework detected
This can be picked up by CMake's build system and likely cause the build to
fail. You may need to move this file out of the way to compile CMake.
Warning: Unbrewed dylibs were found in /usr/local/lib.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae, and may need to be deleted.

Unexpected dylibs:
    /usr/local/lib/libntfs-3g.73.dylib    /usr/local/lib/libntfs.9.0.0.dylib    /usr/local/lib/libublio.1.dylib
Warning: Unbrewed .la files were found in /usr/local/lib.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae, and may need to be deleted.

Unexpected .la files:
    /usr/local/lib/libntfs-3g.la    /usr/local/lib/libntfs.la    /usr/local/lib/libublio.la
Warning: Unbrewed .pc files were found in /usr/local/lib/pkgconfig.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae, and may need to be deleted.

Unexpected .pc files:
    /usr/local/lib/pkgconfig/fuse-ext2.pc    /usr/local/lib/pkgconfig/libntfs-3g.pc    /usr/local/lib/pkgconfig/libublio.pc
Warning: Unbrewed static libraries were found in /usr/local/lib.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae, and may need to be deleted.

Unexpected static libraries:
    /usr/local/lib/libntfs-3g.a    /usr/local/lib/libntfs.a    /usr/local/lib/libublio.a
brew doctor  9.90s user 6.04s system 9% cpu 2:39.55 total

make log

make  install-recursive
Making install in src
make  install-am
  CC     cairo-analysis-surface.lo
  CC     cairo-arc.lo
  CC     cairo-array.lo
  CC     cairo-atomic.lo
  CC     cairo-base64-stream.lo
  CC     cairo-base85-stream.lo
  CC     cairo-bentley-ottmann.lo
  CC     cairo-bentley-ottmann-rectangular.lo
  CC     cairo-bentley-ottmann-rectilinear.lo
  CC     cairo-botor-scan-converter.lo
  CC     cairo-boxes.lo
  CC     cairo-boxes-intersect.lo
  CC     cairo.lo
  CC     cairo-cache.lo
  CC     cairo-clip.lo
  CC     cairo-clip-boxes.lo
  CC     cairo-clip-polygon.lo
  CC     cairo-clip-region.lo
  CC     cairo-clip-surface.lo
  CC     cairo-color.lo
  CC     cairo-composite-rectangles.lo
  CC     cairo-compositor.lo
  CC     cairo-contour.lo
  CC     cairo-damage.lo
  CC     cairo-debug.lo
  CC     cairo-default-context.lo
  CC     cairo-device.lo
  CC     cairo-error.lo
  CC     cairo-fallback-compositor.lo
  CC     cairo-fixed.lo
  CC     cairo-font-face.lo
  CC     cairo-font-face-twin.lo
  CC     cairo-font-face-twin-data.lo
  CC     cairo-font-options.lo
  CC     cairo-freelist.lo
  CC     cairo-freed-pool.lo
  CC     cairo-gstate.lo
  CC     cairo-hash.lo
  CC     cairo-hull.lo
  CC     cairo-image-compositor.lo
  CC     cairo-image-info.lo
  CC     cairo-image-source.lo
  CC     cairo-image-surface.lo
  CC     cairo-lzw.lo
  CC     cairo-matrix.lo
  CC     cairo-mask-compositor.lo
  CC     cairo-mesh-pattern-rasterizer.lo
  CC     cairo-mempool.lo
  CC     cairo-misc.lo
  CC     cairo-mono-scan-converter.lo
  CC     cairo-mutex.lo
  CC     cairo-no-compositor.lo
  CC     cairo-observer.lo
  CC     cairo-output-stream.lo
  CC     cairo-paginated-surface.lo
  CC     cairo-path-bounds.lo
  CC     cairo-path.lo
  CC     cairo-path-fill.lo
  CC     cairo-path-fixed.lo
  CC     cairo-path-in-fill.lo
  CC     cairo-path-stroke.lo
  CC     cairo-path-stroke-boxes.lo
  CC     cairo-path-stroke-polygon.lo
  CC     cairo-path-stroke-tristrip.lo
  CC     cairo-pattern.lo
  CC     cairo-pen.lo
  CC     cairo-polygon.lo
  CC     cairo-polygon-intersect.lo
cairo-polygon-intersect.c: In function '_cairo_bo_sweep_line_compare_edges':
cairo-polygon-intersect.c:447: note: 'ax' was declared here
cairo-polygon-intersect.c:447: note: 'bx' was declared here
  CC     cairo-polygon-reduce.lo
cairo-polygon-reduce.c: In function '_cairo_bo_sweep_line_compare_edges':
cairo-polygon-reduce.c:448: note: 'ax' was declared here
cairo-polygon-reduce.c:448: note: 'bx' was declared here
  CC     cairo-raster-source-pattern.lo
  CC     cairo-recording-surface.lo
  CC     cairo-rectangle.lo
  CC     cairo-rectangular-scan-converter.lo
  CC     cairo-region.lo
  CC     cairo-rtree.lo
  CC     cairo-scaled-font.lo
  CC     cairo-shape-mask-compositor.lo
  CC     cairo-slope.lo
  CC     cairo-spans.lo
  CC     cairo-spans-compositor.lo
  CC     cairo-spline.lo
  CC     cairo-stroke-dash.lo
  CC     cairo-stroke-style.lo
  CC     cairo-surface.lo
  CC     cairo-surface-clipper.lo
  CC     cairo-surface-fallback.lo
  CC     cairo-surface-observer.lo
  CC     cairo-surface-offset.lo
  CC     cairo-surface-snapshot.lo
  CC     cairo-surface-subsurface.lo
  CC     cairo-surface-wrapper.lo
  CC     cairo-time.lo
  CC     cairo-tor-scan-converter.lo
  CC     cairo-tor22-scan-converter.lo
  CC     cairo-clip-tor-scan-converter.lo
  CC     cairo-toy-font-face.lo
  CC     cairo-traps.lo
  CC     cairo-tristrip.lo
  CC     cairo-traps-compositor.lo
  CC     cairo-unicode.lo
  CC     cairo-user-font.lo
  CC     cairo-version.lo
  CC     cairo-wideint.lo
  CC     cairo-cff-subset.lo
  CC     cairo-scaled-font-subsets.lo
cairo-scaled-font-subsets.c: In function '_cairo_scaled_font_subsets_map_glyph':
cairo-scaled-font-subsets.c:603: note: 'font_utf8_len' was declared here
cairo-scaled-font-subsets.c:602: note: 'font_utf8' was declared here
cairo-scaled-font-subsets.c:601: note: 'font_unicode' was declared here
  CC     cairo-truetype-subset.lo
  CC     cairo-type1-fallback.lo
  CC     cairo-type1-glyph-names.lo
  CC     cairo-type1-subset.lo
  CC     cairo-type3-glyph-surface.lo
cairo-type1-subset.c: In function '_cairo_type1_subset_init':
cairo-type1-subset.c:1139: note: 'array_start' was declared here
  CC     cairo-pdf-operators.lo
  CC     cairo-pdf-shading.lo
  CC     cairo-deflate-stream.lo
  CC     cairo-xlib-display.lo
  CC     cairo-xlib-core-compositor.lo
  CC     cairo-xlib-fallback-compositor.lo
  CC     cairo-xlib-render-compositor.lo
  CC     cairo-xlib-screen.lo
  CC     cairo-xlib-source.lo
  CC     cairo-xlib-surface.lo
  CC     cairo-xlib-surface-shm.lo
cairo-xlib-surface-shm.c:54:37: error: X11/extensions/shmproto.h: No such file or directory
cairo-xlib-surface-shm.c: In function '_cairo_xlib_display_init_shm':
cairo-xlib-surface-shm.c:1159: error: 'SHMNAME' undeclared (first use in this function)
cairo-xlib-surface-shm.c:1159: error: (Each undeclared identifier is reported only once
cairo-xlib-surface-shm.c:1159: error: for each function it appears in.)
make[3]: *** [cairo-xlib-surface-shm.lo] Error 1
make[3]: *** Waiting for unfinished jobs....
make[2]: *** [install] Error 2
make[1]: *** [install-recursive] Error 1
make: *** [install] Error 2

HOMEBREW_VERSION: 0.9.3
HEAD: fe737ea4b3d37f392bedf92510f4868a0675574f
CPU: dual-core 64-bit core2
OS X: 10.6.8-i386
Xcode: 3.2.6
X11:  => /usr/X11

Did you get cairo installed? I'm getting this same message.