def invoke_per_goid(self, goid, cmd):
		pc, sp = find_goroutine(goid)
		if not pc:
			print("No such goroutine: ", goid)
			return
		pc = pc_to_int(pc)
		save_frame = gdb.selected_frame()
		gdb.parse_and_eval('$save_sp = $sp')
		gdb.parse_and_eval('$save_pc = $pc')
		# In GDB, assignments to sp must be done from the
		# top-most frame, so select frame 0 first.
		gdb.execute('select-frame 0')