<s>[INST] #include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <time.h>
#include <math.h>

int main (int argc, char *argv[]) {
    char* p;
    p = getenv("PATH");
    if (p == NULL) {
        printf("Error, PATH environment variable is not set.\n");
        exit(1);
    }
    for (int i = 0; p[i] != '\0'; i++) {
        if (p[i] == ':' && p[i + 1] == ':') {
            printf("Error, empty directory in PATH.\n");
            exit(1);
        }
    }
    printf("PATH = %s\n", p);
    return 0;
}

This program is supposed to detect empty directories in the PATH environment variable. However, it has a bug. What's the bug and how do you debug and fix it?[/INST]