When mpg321 gets a filename including a path, it prints a line with the text "Directory: %s/\n", where %s is the name of the directory. So if it gets "/usr/sound.mp3" on the command line, it prints "Directory: /usr/". It should not print the trailing /. This loops particularly stupid when it gets "/sound.mp3" and prints "Directory: //\n".
Created attachment 213072 [details, diff] patch that fixes the issue
media-sound/mpg123-1.9.2 does not have this problem. It prints the string exactly as in mpg321 with my patch applied. so I will just use mpg123 instead.
http://sourceforge.net/tracker/?func=detail&aid=3036864&group_id=36274&atid=416542 Closing as UPSTREAM, if they want it, we will get it with next version.