A method for setting a breakpoint includes the following: receiving an input specifying a location for insertion of a breakpoint in the executable program; determining a breakpoint address for insertion of the breakpoint in the executable program based on the specified location of the breakpoint; writing a breakpoint instruction into a second machine-accessible medium at the breakpoint address; and locking a line containing the breakpoint instruction into the second machine-accessible medium to prevent the breakpoint instruction from being overwritten.