LLDB running a Python debugging script. I'm getting error: invalid thread

I'm trying to run a Python debug script in LLDB, but I'm getting invalid thread errors. I'm not sure why.

Here are my programs:

main.c:

#include <stdio.h>
#include <stdlib.h>

int addNumbs(int a, int b)
{
    return a+b;
}

    int main()
    {
        int a =5;
        int b= 24;
    
        int total = addNumbs(a,b);
    
        printf("%d\n", total);
    
        return 0;
    }

My python debugging script debugersample.py:

import lldb

debugger = lldb.debugger

debugger.HandleCommand("b main")
debugger.HandleCommand("r")

for i in range(0,3):                #execute next 3 times
    debugger.HandleCommand("n")

debugger.HandleCommand("bt")

Running LLDB:

clang -g main -o main
lldb ./main
(lldb) command script import debugsample.py

Breakpoint 1: where = main`main + 15 at main.c:11:9, address = 0x0000000100003f0f
Process 5344 launched: '/Users/xxxx/CLionProjects/C_Practice/main' (x86_64)
error: invalid thread
error: invalid thread
error: invalid thread
error: invalid thread
Process 5344 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
    frame #0: 0x0000000100003f0f main`main at main.c:11:9
   8    
   9    int main()
   10   {
-> 11       int a =5;
   12       int b= 24;
   13   
   14       int* ptr = (int*)malloc(sizeof(int));
Target 0: (main) stopped.

Note: When I run these commands in LLDB Python's interactive interpreter line by line, it works fine.