RF edges generating incorrectly for local struct members

[Daniel-A-W]

Ran into this issue trying to verify a program, I've written up a small MWE below.

The reader thread should be picking up its own store to f.wait, but the tool reports a read from uninitialised memory.
If run with -cache-instructions, it gives an internal error.
Also, the execution time estimate is shown as "-nans".

Replacing the local declaration with a globally declared variable (but not adding any additional writes) fixes the issue.
Replacing the struct with a single atomic int also appears to fix it.

#include <pthread.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdatomic.h>
#include <genmc.h>

struct flag {
   _Atomic unsigned int wait ;
};

#define FLAGS 1

_Atomic (struct flag*) flags[FLAGS];
pthread_t writer;
pthread_t reader;

void* read(void* i) {
  struct flag f;
  _Atomic struct flag* p = &f;
  atomic_store_explicit(&flags[(int)i], p, memory_order_release);
  atomic_store_explicit(&f.wait, 1, memory_order_release);
  while (atomic_load_explicit(&f.wait, memory_order_relaxed));
  pthread_join(&writer, NULL);
}

void* write(void* p) {
  for(int i = 0; i < FLAGS; i++) {
    struct flag* f;
    do {f = atomic_load_explicit(&flags[i], memory_order_acquire);}
    while (f == NULL);
    atomic_store_explicit(&f->wait, 0, memory_order_relaxed);
  }
}

int main() {
	pthread_create(&writer, NULL, &write, NULL);
	pthread_create(&reader, NULL, &read, (void*)0);
	pthread_join(reader, NULL);
	pthread_join(writer, NULL);
}