libzzip won't build correctly with clang

[david.reitter@…]

libzzip fails to build. It tries to build with clang and fails with the error message:

:info:build /bin/sh ../libtool --silent --tag=CC   --mode=link /Developer/usr/bin/clang  -O2 -arch i386 -arch x86_64 -D_USE_MMAP  -fomit-frame-pointer -Wall -Wpointer-arith -Wsign-compare -Wmissing-declarations -Wdeclaration-after-statement -Werror-implicit-function-declaration -Wstrict-aliasing -Warray-bounds -fstrict-prototypes -Wstrict-prototypes --export-dynamic -L/opt/local/lib -arch i386 -arch x86_64 -o zzipwrap zzipwrap.o libzzipwrap.la   
:info:build clang: error: unsupported option '--export-dynamic'

The build commands were

{{{sudo port uninstall libzzip sudo port clean libzzip sudo port install libzzip +universal}}}

As a workaround, I managed to install libzzip with the following trick:

sudo port install libzzip +universal configure.compiler=llvm-gcc-4.2

See also #30849