function blabla {
  echo IN blabla OUT
}

function exit {
  local error_code stack_lines stack_functions stack_sources
  error_code=${1:-0}

  stack_lines=("${BASH_LINENO[@]}")
  stack_functions=("${FUNCNAME[@]}")
  stack_sources=("${BASH_SOURCE[@]}")

  unset stack_functions[0]
  unset stack_sources[0]
  unset stack_lines[-1]
  if [[ $error_code > 0 ]]; then
    printf "\nEXIT #${error_code} due to error at line ${stack_lines} : \n-----------------------------------------\n"
    [[ -s /tmp/error ]] && echo -ne 'CAUSE:\t\t' && cat /tmp/error
    echo -e "FUNCNAME:\t${stack_functions[@]}" >&2 # inner outer main
    echo -e "BASH_SOURCE:\t${stack_sources[@]}" >&2
    echo -e "BASH_LINENO:\t${stack_lines[@]}" >&2
    trap - ERR TERM INT EXIT
    builtin exit "${error_code}"
  else
    echo __REAL_SUCCESS
  fi
}

function _backtrace_perform {
  echo LAUNCH script...
  export -f exit
  export -f blabla
  set -TEue
  trap 'exit $?' ERR TERM INT EXIT

  source=${BASH_SOURCE[-1]}
  _BACKTRACE=true
  export _BACKTRACE

  echo call1 exec $source $*
  bash -c "set -TEue; trap 'exit $?' ERR TERM INT EXIT; source $source $*" 3>&1 1>&2 2>&3 | tee /tmp/error

  trap - ERR TERM INT EXIT
  builtin exit
  echo NOT VISIBLE

}

_BACKTRACE=${_BACKTRACE:-false}
echo _BACKTRACE=${_BACKTRACE}
${_BACKTRACE} && return
_backtrace_perform