Various technologies and techniques are disclosed for providing a debugger for programs running under a transactional memory system. When running a particular program using the debugger, the system detects when a conflict occurs on at least one conflictpoint that was set in the particular program. A graphical user interface is provided that displays information related to the detected conflict. The graphical user interface can display transactional state and/or other details independently of a conflict. A conflictpoint can be assigned to one or more regions of source code in one or more transactions in the particular program. A conflictpoint can also be assigned to a particular variable in the particular program. When running the particular program in a debug mode, execution is stopped if a conflict occurs on any of the conflictpoints.