+
−-*- mode: outline -*-
+
−
+
−* Debugging.
+
−
+
−** Using edebug.
+
−
+
−Execute ‘M-x edebug-defun’ (also on ‘C-u C-M-x’) on defun in source code to
+
−enable debugging for desired function. When next time this function invoked
+
−you entered to its debugging (jamped to its source code).
+
−
+
−To start debug execute code which used debugged function.
+
−
+
−You can disable edebug on a function by evaluating the function again using
+
−‘C-M-x’.
+
−
+
−** How debug func?
+
−
+
−Use M-x debug-on-entry and M-x cancel-debug-on-entry to control
+
−which functions will enter the debugger when called.
+
−
+
−When next time that function called automatically loaded debug-mode.
+
−
+
−** How debug ini file?
+
−
+
−When your InitFile has a bug, or when you load external files that cause
+
−errors, the bug is often hard to find, because the Emacs Lisp reader does not
+
−know about line numbers and files – it just knows an error happened, and
+
−that’s it.
+
−
+
−*** Binary Search.
+
−
+
−Select half of the file in a region, and M-x eval-region. Depending on whether
+
−that causes the error or not, split this half or the other half again, and
+
−repeat.
+
−
+
−*** Elisp.
+
−
+
− - Use a keyboard macro that moves forward one expression (sexp) and evaluates
+
−   it.
+
− - Try C-x check-parens.
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− - Set (setq debug-on-error t).
+
−
+
−*** CLI.
+
−
+
−  $ emacs --no-init-file --no-site-file --debug-init
+
−
+
−*** Simplified Binary Search.
+
−
+
−Add (error “No error until here”) in the middle of your file. If you get the
+
−error “No error until here” when reloading the file, move the expression
+
−towards the back of the file, otherwise towards the front of the file.