NIOS : fopen command only works if using the NIOSII Debug tool

I am trying to read a file using NIOS with the eventual goal of loading that readdata into an EEPROM.

I have followed the instructions outlined in : https://www.intel.com/content/www/us/en/programmable/documentation/mwh1416947091611.html

I have gone to the BSP editor -> Software Packages and enabled altera_hostfs. The hostfs_name is /mnt/host

My code (included below) gets stuck at fopen but if I use the NIOSII debugger, I am able to step through the whole program and readout "Hello World" into the console. Any suggestions would be appreciated.

#include <stdio.h>

#include <alt_types.h>

#include <io.h>

#include <string.h>

#include <stdlib.h>

#include <unistd.h>

#define BUF_SIZE (12)

void main()

{

FILE* fp;

char buffer[BUF_SIZE];

printf("start\n");

fp = fopen("/mnt/host/read_test.txt", "r");

printf("fopen command\n");

if (fp == NULL)

{

printf ("connot open file for reading\n");

exit(1);

}

fread(buffer, BUF_SIZE, 1, fp);

fclose(fp);

printf("%s", buffer);

}