I had read the following about passing arguments to variadic functions,
/a/3530807/22299201

#include<stdio.h>
#include<string.h>
#include<stdarg.h>

#define BUF_SIZE 1024

void foo(char*, ...);
void wrapper(char*, va_list);
void bar(char*, ...);

int main() {
    char *format = "Unit testing this function %s";
    
    foo(format, "args1");

    return 0;
}

void foo(char *format, ...) {
    // code to capture output
    va_list args;
    va_start(args, format);
    char *temp = va_arg(args, char*);
    printf("args foo %sn", temp);
    wrapper(format, args);
    va_end(args);
    // code to capture output
}

void bar(char *format, ...) {
    char buffer[BUF_SIZE];
    va_list args;
    va_start(args, format);
    char *temp = va_arg(args, char*);
    printf("args bar %sn", temp);
    vsprintf(buffer, format, args);
    printf("%sn", buffer);
    va_end(args);
}

void wrapper(char* format, va_list args) {
    bar(format, args);
    char *temp = va_arg(args, char*);
    printf("args wrapper %sn", temp);
}

Output:

args foo args1
args bar 
Unit testing this function 
args wrapper args1

Let me explain the scenario:-

• I have to unit test a production function with a similar signature and logic as bar.
• I am using acutest framework to test my code, main here can resemble that test function.
• I am using a helper function, foo that has some logic to capture output of bar.
• Based on the above link shared, it is impossible to pass variable arguments from foo to bar, hence passing to another wrapper func.

Why are args not being propogated to bar?
What am I doing wrong?