See objs/app/app.htm for details about stack sizes for functions and call tree. Stack usage for std::cout << (double) is about 1336 bytes Stack usage for CppUTest is at least 4368 bytes with call chain: main -> CommandLineTestRunner::RunAllTests(int, char**) -> CommandLineTestRunner::RunAllTests(int, const char**) -> MemoryLeakWarningPlugin::MemoryLeakWarningPlugin(const SimpleString&, MemoryLeakDetector*) -> MemoryLeakWarningPlugin::getGlobalDetector() -> MemoryLeakDetector::MemoryLeakDetector(MemoryLeakFailure*) -> MemoryLeakDetectorTable::MemoryLeakDetectorTable() -> __aeabi_vec_ctor_nocookie_nodtor Maximum stack consumption for constructor MemoryLeakDetector::MemoryLeakDetector(MemoryLeakFailure*)