Determining what's in a port

[Michael]

Is there a way to determine what's in an in-active port?
Attempting to ask "contents" does not work.

Here's what does *not* work:

bash-3.2# port installed x264
The following ports are currently installed:
  x264 @20160119_0
  x264 @20161201_0 (active)
  x264 @20170522_0
  x264 @20171225_0
bash-3.2# port contents x264
Port x264 contains:
  /opt/local/bin/x264
  /opt/local/include/x264.h
  /opt/local/include/x264_config.h
  /opt/local/lib/libx264.148.dylib
  /opt/local/lib/libx264.a
  /opt/local/lib/libx264.dylib
  /opt/local/lib/pkgconfig/x264.pc
bash-3.2# ffmpeg
dyld: Library not loaded: /opt/local/lib/libx264.152.dylib
  Referenced from: /opt/local/bin/ffmpeg
  Reason: image not found
Trace/BPT trap: 5
bash-3.2# port contents x264 @20170522_0
Port x264 contains:
  /opt/local/bin/x264
  /opt/local/include/x264.h
  /opt/local/include/x264_config.h
  /opt/local/lib/libx264.148.dylib
  /opt/local/lib/libx264.a
  /opt/local/lib/libx264.dylib
  /opt/local/lib/pkgconfig/x264.pc
bash-3.2# port contents x264 @20171225_0
Port x264 contains:
  /opt/local/bin/x264
  /opt/local/include/x264.h
  /opt/local/include/x264_config.h
  /opt/local/lib/libx264.148.dylib
  /opt/local/lib/libx264.a
  /opt/local/lib/libx264.dylib
  /opt/local/lib/pkgconfig/x264.pc
bash-3.2#