can't (Debug) attach to unstarted application unless introducing some delay

"Debug" menu->Start debugging->Attach to unstarted application

does not work unless you introduce some delay in the code.

Here how to reproduce on Linux (Fedora 35 in my case). Compile following code

#include <stdio.h>

int main()
{
    printf("hello world\n");
    return 0;
}

with

$ gcc -g3 main.c -Wall -Wextra -o hello_world

then in QtCreator

"Debug" menu->Start debugging->Attach to unstarted application

then in your computer shell

./hello_world

Nothing will happen in QtCreator
If instead you use the following code, QtCreator debug interface will correctly attach to the process

#include <stdio.h>

int main()
{
    sleep(1);
    printf("hello world\n");
    return 0;
}