Generating Memgraph with leaks tool in a UI test does not generate backtraces.

I have an XCUITest and in the course of the test, in tearDown for eg. I call the leaks tool on the application and generate a memgraph.

% leaks App_Name --outputGraph=~/Desktop/Foo.memgraph

Before launching the application, I set MallocStackLogging so that the backtraces are present.

XCUIApplication *app = [[XCUIApplication alloc] init];  
NSMutableDictionary *launEnv = [app.launchEnvironment mutableCopy];
[launEnv setObject:@"1" forKey:@"MallocStackLoggingNoCompact"];
app.launchEnvironment = launEnv;

If I pause the application process in the course of the test, and open the Memory Graph Debugger, the entire call trace is present for a leak.
On calling the above command, the leaks file is found to contain the call trace however the memgraph only contains

0 malloc_zone_calloc
49 _main_thread

for all objects. Also, calling the leaks command provides the following output:

Invalid connection: com.apple.coresymbolicationd
Region __TEXT __objc_methname [7fff2731d13e -> 1b43) outside of relocations in mmap SOD
Region __TEXT __objc_methname [7fff2731d13e -> 1b43) outside of relocations in mmap SOD
Region __TEXT __objc_methname [7fff2731d13e -> 1b43) outside of relocations in mmap SOD
Region __TEXT __objc_classname [7fff23e244b0 -> 11f8) outside of relocations in mmap SOD
Region __TEXT __objc_classname [7fff258aabe4 -> 5175) outside of relocations in mmap SOD
Region __TEXT __objc_classname [7fff47c7c5e4 -> 20970) outside of relocations in mmap SOD
Region __TEXT __objc_classname [7fff209eb2f4 -> 4f9f) outside of relocations in mmap SOD
etc.