the main thread stack size used in this run was 8388608

The main thread stack size used in this run was 8388608 bytes. This is the amount of memory allocated for the main thread to use as its stack space during the execution of the program. The stack is used to store local variables, function calls, and other execution context information. It is important to allocate enough stack space to prevent stack overflow errors, which can occur when the stack grows beyond its allocated size.