I found a fold bug when reading the source code of rebar
It appears on the function commands/0 in line 414 of rebar.erl.
I roughly read the erlang.vim, found it is because the line 454 of rebar.erl

 _tests module.

matchs the regx

s:erlang_fun_end   = '^[^%]*\.\s*\(%.*\)\?$'  

It seems there is no method to fix this bug, because vim fold lines one by one and can not know it is a string.

Do you think so?