use special valgrind option to detect memory leaks

I am hoping that this task fails now

allocator.h

@@ -93,8 +93,7 @@ allocator_t borrow_allocator_interface(borrow_allocator_t *this);
 // Using the return a keyword in the statement following this macro will cause
 // a guaranteed memory leak.
 #define with_borrow(NAME) \
-    borrow_allocator_t UNIQUE = borrow_allocator_create(); \
-    for (allocator_t NAME = borrow_allocator_interface(&UNIQUE); !UNIQUE.head; UNIQUE.head = (borrow_allocator_reset(&UNIQUE), (linked_allocation_node_t*) 1)) \
+    for (allocator_t NAME = borrow_allocator_interface(&borrow_allocator_create()); !((borrow_allocator_t*)NAME.this)->head; ((borrow_allocator_t*)NAME.this)->head = (borrow_allocator_reset(((borrow_allocator_t*)NAME.this)), (linked_allocation_node_t*) 1)) \
     for (int UNIQUE = 0; UNIQUE < 1; UNIQUE++)
 
 #ifdef ALLOCATOR_IMPLEMENTATION

makefile

@@ -16,7 +16,7 @@ test:
 		echo "Compiling all test files into $(TESTBIN)..."; \
 		$(CC) $(CFLAGS) _allocator_impl.c $$files -o $(TESTBIN) $(LDFLAGS) || exit 1; \
 		echo "Running tests..."; \
-		valgrind $(TESTBIN); \
+		valgrind --trace-children=yes $(TESTBIN); \
 	fi
 
 

test_borrow_allocator.c

@@ -11,11 +11,15 @@ Test(borrow_allocator, test) {
     borrow_allocator_reset(&balloc);
     cr_assert_eq(0, borrow_allocator_count_allocations(&balloc));
     borrow_allocator_assert_all_freed(&balloc);
+    void *foobar = malloc(1000);
+    (void)foobar;
 }
 
 #define IS_SIZE 900
 Test(borrow_allocator, with) {
     with_borrow(foo) {
+        with_borrow(bar) {
+        } 
         int *is = allocator_alloc(foo, sizeof(int) * IS_SIZE);
         for (int i = 0; i < IS_SIZE; i++) is[i] = i;
         is = allocator_alloc(foo, sizeof(int) * IS_SIZE);