The log says:
:info:activate dyld: Library not loaded: /opt/local/lib/libgmodule-2.0.0.dylib
:info:activate Referenced from: /opt/local/bin/gdk-pixbuf-query-loaders
:info:activate Reason: Incompatible library version: gdk-pixbuf-query-loaders requires version 4201.0.0 or later, but libgmodule-2.0.0.dylib provides version 4001.0.0
Looks like your glib2 port (which provides /opt/local/lib/libgmodule-2.0.0.dylib) is unexpectedly outdated. Please try running "sudo port upgrade glib2". If that doesn't do anything, try forcibly rebuilding it with "sudo port -n upgrade --force glib2".