[cairo] Re: pycairo link error on Mac OS X

[Jeremy Brewer]

I ran 'make check' after rebuilding cairo, and it fails on a lot of  
tests complaining about functions starting with CG* (Quartz  
functions).  After some trial and error I determined that these  
errors are due to configuring with --enable-quartz and --enable- 
atsui.  More specifically, anytime that a program is linked against  
libpng dynamically and uses Quartz or atsui (-framework CoreServices - 
framework ApplicationServices) there will be a runtime error because  
of the case-sensitivity of libPng and libpng.

I encountered a similar problem when trying to build libjpeg for the  
Python Imaging Library, and I eventually gave up on getting the  
dynamic libs to work and only used static libs.

To get cairo and pycairo working, I removed the dynamic libpng libs  
and created a symlink libpng12.dylib that points to the static lib.   
I did the latter because the cairo build explicitly names  
libpng12.dylib when linking instead of -lpng, but I couldn't find  
where it was explicitly stated in the Makefile (grep -r  
libpng12.dylib * yields nothing, and my pkg-config scripts didn't  
seem to have anything either).

To get pycairo to compile, I had to alter the LDFLAGS environment  
variable before configuring as below:

setenv LDFLAGS '-Xlinker -framework -Xlinker CoreServices -Xlinker - 
framework -Xlinker ApplicationServices'

I figured out how to do this from the following web site detailing  
freetype issues with Mac OS X:

http://www.nabble.com/Failure-of-fontconfig-compilation-on-Mac-OS- 
X-10.3.9-t2356685.html

Only if cairo statically links libpng will this not cause a runtime  
error for me because of the case sensitivity issue mentioned above.

I hope someone finds this info helpful as I spent several hours  
tinkering with this stuff.

Jeremy