gistfile1.txt

$ rvm_archflags="-arch i386 -arch x86_64" ARCHFLAGS="-arch i386 -arch x86_64" CFLAGS='-arch i386 -arch x86_64' LDFLAGS='-arch i386 -arch x86_64' rvm pkg install zlib      
Fetching zlib-1.2.5.tar.gz to /Users/rbates/.rvm/archives
Extracting zlib-1.2.5.tar.gz to /Users/rbates/.rvm/src
Configuring zlib in /Users/rbates/.rvm/src/zlib-1.2.5.
Compiling zlib in /Users/rbates/.rvm/src/zlib-1.2.5.
ERROR: Error running '/usr/bin/make ', please read /Users/rbates/.rvm/log/zlib/make.log
Installing zlib to /Users/rbates/.rvm/usr
ERROR: Error running '/usr/bin/make install', please read /Users/rbates/.rvm/log/zlib/make.install.log

$ cat /Users/rbates/.rvm/log/zlib/make.log
[2011-08-02 10:45:26] /usr/bin/make 
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o example.o example.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o adler32.o adler32.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o compress.o compress.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o crc32.o crc32.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o deflate.o deflate.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o gzclose.o gzclose.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o gzlib.o gzlib.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o gzread.o gzread.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o gzwrite.o gzwrite.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o infback.o infback.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o inffast.o inffast.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o inflate.o inflate.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o inftrees.o inftrees.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o trees.o trees.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o uncompr.o uncompr.c
gcc -arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp   -c -o zutil.o zutil.c
ar rc libz.a adler32.o compress.o crc32.o deflate.o gzclose.o gzlib.o gzread.o gzwrite.o infback.o inffast.o inflate.o inftrees.o trees.o uncompr.o zutil.o 
ar: libz.a is a fat file (use libtool(1) or lipo(1) and ar(1) on it)
ar: libz.a: Inappropriate file type or format
make: *** [libz.a] Error 1