Didn't work. It looks like the emu is crashing before creating the fceux.cfg file, so i created it manually and added that line, but I get the same error. Probably creating the file with only that line is not the best thing to do. Can yo upload your fceux.cfg?
EDIT: It DOES create some subfolders inside $HOME/.fceux/ and they're all empty. Maybe that helps in some way.
Also, can you upload the source? Maybe I can help searching what's wrong.