x264: Cannot build due to missing library

[seifert@…]

I'm attempting to build the x264 port using OS 10.6.6. I removed all of my ports and am trying to install from a fresh build. I always run into the following error:

:info:build /usr/bin/gcc-4.2 -o x264 x264.o input/timecode.o input/yuv.o input/y4m.o output/raw.o output/matroska.o output/matroska_ebml.o output/flv.o output/flv_bytestream.o input/thread.o input/lavf.o libx264.a -L/opt/local/lib -arch x86_64 -arch x86_64 -lm -arch x86_64 -lpthread -s -L. -lavformat -lswscale -lavcodec -lavutil -lm -lz -lbz2 -lpthread 
:info:build ld: warning: option -s is obsolete and being ignored
:info:build ld: library not found for -lavformat
:info:build collect2: ld returned 1 exit status
:info:build make: *** [x264] Error 1

How can I get libavformat to be built?

[seifert@…]

Full log file from build

[devans@…]

Can't reproduce this problem with the current version of x264. Please

sudo port selfupdate
sudo port clean x264
sudo port install x264