c++ - iOS: execl(3) doesn't work anymore -

i'm trying call execl within ios application, running in iphone simulator. fails. xcode shows error:

error: address doesn't contain section points section in object file

when going step step, error pops @ moment when try step execl.

so, makes me think there problem specific method. doesn't exist in compiled executable? need link specific libraries? tried well:

printf("execl(): %llx", &execl); // address of method 

which prints values like: execl(): 3aeee0e. however, when debugging states: exc_bad_access , thread 1: 0x0000000.

any ideas? tried methods execve(), give exact same result. in past, exact same code work perfect.

_{for know i'm talking about: yes, want use valgrind , not tools apple.}