linker comman failed with exit code of 1 in find.c

Question

I was about to submit pset3 and pset4 which I have completed, but in the process of keeping my house in order by checking every code before submission, I discovered that helpers.c has developed issues. When I make find I receive this information from the compiler:

clang -ggdb3 -O0 -std=c11 -Wall -Werror -o find find.c helpers.c -lcs50 -lm
/tmp/find-b1555f.o: In function `main':
/home/ubuntu/workspace/pset3/find/find.c:55: undefined reference to `sort'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [find] Error 1

As a result, of course, it failed check50, which gave this advice:

helpers.c exists helpers.c compiles ! Fix the following dependencies first:   
helpers.c exists finds 42 in {42,43,44} ! Fix the following dependencies first:   
helpers.c compiles finds 42 in {41,42,43} !   Fix the following dependencies first:   
helpers.c compiles finds 42 in {40,41,42} !   Fix the following dependencies first:   
helpers.c compiles finds 42 in {41,42,43,44} !    Fix the following dependencies first:   
helpers.c compiles finds 42 in {40,41,42,43} !    Fix the following dependencies first:   
helpers.c compiles finds 42 in {39,40,41,42} !    Fix the following dependencies first:   
helpers.c compiles doesn't find 42 in {39,40,41}

Please, can someone be kind enough to advise me what to do. I have checked, all the files are intact. My only suspicion is the bubble sort code I wrote and cannot see why It should be complaining of it. Here, is a snipet of the code:

#include <stdio.h>
#include <cs50.h>

void BubbleSort(int values[], int n)
{
    // TODO: implement an O(n^2) sorting algorithm

    for (int i = values[n - 1]; i >= 0; i--)
    {
       for (int j = 0; j <= i; j++)
       {
           if (values[j - 1] > values[j])
           {
               int temp = values[j - 1];
               values[j - 1] = values[j];
               values[j] = temp;
           }
       }
    }
    return;
}

Answer 1

find calls functions sort and search, maybe you removed/renamed sort? It has to have the correct signature, too (same number and types of arguments).