Mac OS X 64 bit: dependencies problems

[Greyzard]

hi guys!
can somebody help me?
if i try to install the depencencies for the dolphin emulator in mac os x, the terminal give me the following error:

Error: Target org.macports.configure returned: configure failure: shell command " cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_audio_libao/work/libao-0.8.8" && ./configure --prefix=/opt/local --disable-arts --disable-esd --disable-oss --disable-X " returned error 77
Command output: checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... ./install-sh -c -d
checking for gawk... no
checking for mawk... no
checking for nawk... no
checking for awk... awk
checking whether make sets $(MAKE)... no
checking whether to enable maintainer-specific portions of Makefiles... no
checking build system type... i386-apple-darwin9.6.0
checking host system type... i386-apple-darwin9.6.0
checking for gcc... /usr/bin/gcc-4.0
checking for C compiler default output file name...
configure: error: C compiler cannot create executables
See `config.log' for more details.

Error: Status 1 encountered during processing.

i have mac os X 10.5.6 (if it's incorrect, the latest, i think) at 64 bit