need help debugging otp app

[Garry Hodgson]

i'm trying to get my first otp application working, based on ulf's 
release handling tutorial.  i've got most of the plumbing together,
with the right directory structure and all, and build a .boot file
from a .rel file.  when i try and run it, though, i get:

--> erl -boot ./master -config ./sys -boot_var MYAPPS $DIR -sname n1
Error in process <0.1.0> with exit value: {badarg,[{erlang,'++',[<<6 bytes>>," in bootfile"]},{init,append,2},{init,concat,1},{init,get_var_value,2},{init,add_var,2},{init,fix_path,2},{init,make_path,4},{init,eval_script,7},{init,do_boot,3}]}
{"init terminating in do_boot",{badarg,[{erlang,'++',[<<6 bytes>>," in bootfile"]},{init,append,2},{init,concat,1},{init,get_var_value,2},{init,add_var,2},{init,fix_path,2},{init,make_path,4},{init,eval_script,7},{init,do_boot,3}]}}
init terminating in do_boot ()

i've tracked down various errors in the code while trying to fix this, 
but this result doesn't change (despite building it all to a clean directory
structure each time).  and i just don't understand what it's telling me.

so, short of posting all my code here to bore everyone, i could use
some advice on what this error means, or how to proceed in
debugging it.

thanks

----
Garry Hodgson, Technical Consultant, AT&T Labs

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