The trap command with printing the lines didn't work. Had to change it to drop the parantheses, then it worked, like this trap 'read -p "[${BASH_SOURCE:-}:${L

The trap command with printing the lines didn't work. Had to change it to drop the parantheses, then it worked, like this trap 'read -p "[${BASH_SOURCE:-}:${LINENO:-}] ${BASH_COMMAND:-}"' DEBUG