A method, computer-readable storage medium, and computer system are provided. In an embodiment, in response to a command that requests setting a breakpoint at a line in a module, a determination is made whether a snapshot instruction exists before a machine instruction that implements a source statement at the line. If the snapshot instruction exists before the machine instruction that implements the source statement at the line, the breakpoint is set at the machine instruction that implements the source statement at the line. If the snapshot instruction does not exist before the machine instruction that implements the source statement at the line, the module is recompiled to add the snapshot instruction before the machine instruction that implements the source statement.