Good morning Sir/Mam
i want to read data on serial using nrf9160 by segger. i have pic a sample from devzone "Uart". i have successfully build it and Run on board , but want to go with build and debug .
on starting debugging debug stop with following error.

code is.
#include <zephyr.h>
#include <device.h>
#include <devicetree.h>
#include <drivers/uart.h>
static uint8_t uart_buf[1024];
void uart_cb(const struct device *x, void *user_data)
{
uart_irq_update(x);
int data_length = 0;
if (uart_irq_rx_ready(x)) {
data_length = uart_fifo_read(x, uart_buf, sizeof(uart_buf));
uart_buf[data_length] = 0;
}
uart_fifo_fill(x, uart_buf, data_length);
}
void main(void)
{
const struct device *uart = device_get_binding("UART_2");
uart_irq_callback_set(uart, uart_cb);
uart_irq_rx_enable(uart);
uart_fifo_fill(uart, "UART loopback start!\r\n", 22);
printk("UART loopback start!\n"); //output on UART0, which is default for logging
while (1) {printk("UART loopback start!\n"); //output on UART0, which is default for logging
k_cpu_idle();
}
}
please help