The ordinary Lisp debugger provides the ability to suspend evaluation of a form. While evaluation is suspended (a state that is commonly known as a break), you may examine the run time stack, examine the values of local or global variables, or change those values. Since a break is a recursive edit, all the usual editing facilities of Emacs are available; you can even run programs that will enter the debugger recursively. See Recursive Editing.
| • Error Debugging: | Entering the debugger when an error happens. | |
| • Infinite Loops: | Stopping and debugging a program that doesn’t exit. | |
| • Function Debugging: | Entering it when a certain function is called. | |
| • Explicit Debug: | Entering it at a certain point in the program. | |
| • Using Debugger: | What the debugger does; what you see while in it. | |
| • Debugger Commands: | Commands used while in the debugger. | |
| • Invoking the Debugger: | How to call the function debug.
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| • Internals of Debugger: | Subroutines of the debugger, and global variables. |