Meaning of error tuple message when calling start_child/2

Question

I get the following error tuple back when calling start_child/2

{error,
{{[],[]},
    {child,undefined,"i.file_man",
        {sg_file_mgr,start_link,
            ["i.file",
            [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,
            7,568,569,570,571,572,573,574,
            575,576,577,578,579,580,581,582,583,584,
            585,586,587,588,589,590],
            [{"129.16.165.241",6881},
            {"68.189.244.138",55109},
            {"68.10.136.204",51422},
            {"68.10.136.204",51416},
            {"67.174.189.28",6881}],
            <0.400.0>]},
        permanent,2000,worker,
        [sg_file_mgr]}}}

What are those two empty lists in the first tuple if the message and what's undefined?

Answer 1

undefined is because the child is not yet started and inserted into the supervisor. {[], []} is probably a term from the underlying process. Can you manually start_link sg_file_mgr or not?

run erl -boot start_sasl and check if SASL has an interesting error report for you.

What does the init/1 function of sg_file_mgr look like?