The debugger has the following restriction:
The victim system communicates over COM2 if COM2 exists and over COM1 otherwise. The COM port the victim system uses must not be usurped by an application. For example, if the victim system is using COM2 and you issue the following command:
mode com2
you may disrupt communications. The device driver and executables associated with the IBM LAN Management Utilities (for example, LMUIPL.SYS) can also prevent the victim system from communicating.
Similarly, the COM port the host system uses must be dedicated to the debugger. If the debugger fails to attach, make sure you're not running a terminal emulator (for example, T or ZOC) in the background that has the COM port tied up.
Currently, there are limitations with C++ support for the Watcom compiler. The debugger does not support mangled names from the Watcom compiler. This can show up when the debugger can not find certain functions (external functions and overloaded member functions) or sets function breakpoints.