Undefined behavior when disabling AWS
Setting DISABLE_AWS_IOMANAGER=TRUE triggers a bug in IOManager::CreateIOManager() in IOManager.cpp. The ifdef test for OPENVDS_NO_AWS_IOMANAGER should have been one line further up. The bug looks harmless but in fact triggers C++ undefined behavior. It creates a path where this non-void function might fail to return a value. Even if the bad path is not executed, the compiler is allowed to completely trash your program. I have personally seen g++ do just that in a very similar case.
Some but not all compilers detect the problem and report a fatal error.