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There is a page LinkingAndUniversalBinaries under ApplicationLinkingIssues that outlines what happens if you have not, in fact, built universal binaries of the libraries for your project

I’ve been getting my project ready to be compiled as a Universal binary, but I’ve hit a snag: my project uses several static libraries, which are for the moment PPC only, and I would need to have universal versions of these to properly build a universal app.

Are there any pointers available on how to build universal libraries (the .a and .dylib kind)?

That’s a pretty general question, and the answer isn’t really much different from how you build a universal application. Is there a particular step in the process that you’re having trouble with?

I’m trying to build an open-source library (I’ll leave it at that, since being more specific generally won’t help future readers, and this is likely to be a ‘common problem’ for general OS code anyways), so it’s the kind that you do ‘./configure, make, make install’; I’ve tried inserting the custom environment variables between the .configure and make commands as described at but all I ever get is only ppc binaries. I’m guessing maybe further changes are needed in the makefile, but I haven’t a clue on what to look for or do (I usually just use libraries, not compile them).

Check out this article:

when I try it on the code I’m trying to compile, configure croaks with those settings:

… checking for gcc… gcc checking for C compiler default output file name… configure: error: C compiler cannot create executables See `config.log’ for more details.

and the relevant portion of the log:

… configure:2072: checking for C compiler default output file name configure:2075: gcc -isysroot /Developer/SDKs/MacOSX10.4u.sdk -arch i386 -arch ppc -Wl,-syslibroot,/De veloper/SDKs/MacOSX10.4u.sdk conftest.c >&5 /usr/bin/ld: -syslibroot: multiply specified collect2: ld returned 1 exit status /usr/bin/ld: -syslibroot: multiply specified collect2: ld returned 1 exit status lipo: can’t open input file: /var/tmp//ccpHzug6.out (No such file or directory) configure:2078: $? = 1 configure: failed program was: …

a search for this “-syslibroot: multiply specified” error yields that this seems to be a common problem, with no clear solution that I have yet seen.

From, it looks like the -syslibroot stuff is no longer necessary. A project built just fine using this:

env CFLAGS=”-isysroot /Developer/SDKs/MacOSX10.4u.sdk -arch i386 -arch ppc” ./configure –disable-dependency-tracking

Similar to the above code, but if you’re wanting to compile from the command line directly, you can use this:

gcc myapp.c -o myapp -arch i386 -arch ppc -isysroot /Developer/SDKs/MacOSX10.4u.sdk

I was getting tons of “cputype ppc does not match cputype arch i386” general errors, after following Apple’s directions to a T. As it turns out, you have to delete and re-import all the frameworks you use in the app after changing the build settings, and make sure you bring in the frameworks from the 10.4u(niversal binary) SDK in the /Developer folder, and not the standard /System frameworks. If you get any X “expected to be defined by Cocoa” errors, this is the same problem. Otherwise, the Apple instructions are complete, as much as they frustratingly aren’t. -Stephen

I’m not sure what kind of problem you ran into (Xcode is buggy so often) but you shouldn’t have to do what you did. Adding frameworks directly from /System is fine, and keeping your old /System frameworks is also fine. What setting the SDK does is add an implicit search path to all such references, so that it will look in the 10.4u’s /System before looking in the root one.