error when convert trace file

[heiheshang]

`Error in process <7827.24524.146> on node '...' with exit value: {problem,[{eep,save_kcachegrind_format,1,[{file,"eep.erl"},{line,315}]}]}

** exception exit: problem in function eep:save_kcachegrind_format/1 (eep.erl, line 315)`