Replying to yanflao@…:
xcode 2.2.3
Did you mean 3.2.2?
mono 2.4.3 can be installed but with the x86_32 arch
I'm not sure what you mean here. First, the current version of the mono port is 2.6.4; if you see 2.4.3, then your ports are out of date and you should use "sudo port selfupdate" to update. Second, x86_64 is the default arch on Snow Leopard for 64-bit capable machines. i386 is the other arch available. There is no such arch as x86_32.
It sounds like you are trying to build libgdiplus for i386 but its dependencies have not been built for i386:
ld: warning: in /opt/local/lib/libcairo.dylib, file was built for unsupported file format which is not the architecture being linked (i386)
ld: warning: in /opt/local/lib/libpixman-1.dylib, file was built for unsupported file format which is not the architecture being linked (i386)
Rebuild cairo and dependencies so they contain the i386 architecture. You could either build for i386 only, or probably preferable rebuild with the universal variant so they contain both i386 and x86_64:
sudo port upgrade --enforce-variants cairo +universal
ld: in /opt/local/lib/libxslt.1.dylib, file was built for unsupported file format which is not the architecture being linked (i386) for architecture i386
Rebuild libxslt and dependencies with the universal variant:
sudo port upgrade --enforce-variants libxslt +universal