RE: (debug) backtrace: how to show source code at current location.

[Drew Adams]

> Please, how can I find out what's causing this error message:
> 
>   "(wrong-type-argument arrayp tab)"

>From your error message alone, it seems that the symbol `tab' is being passed 
>to
some function that expects an array.  That's not much help yet, but things might
become clearer when you dig deeper using the debugger.

(setq debug-on-error t)

1. Load source (*.el) files for the library where the error occurred.

IOW, look at the `debug-on-error' backtrace to see which function(s) were
involved when the error occurred.  Then use `C-h f' or `find-func' to find the
function definition(s) (source file(s)).  Load the source file(s) (*.el) using
`load-file' or `load-library', including the extension `.el' in the name.

2. Provoke the error and backtrace again.  It should now show more source-code
entry points instead of byte-code (the `(byte-code "ÁÂÃ...' stuff)

3. You can also use `M-x debug-on-entry THE-FUNCTION' to enter the debugger
whenever a problematic function is invoked.  Then you can walk through the
invocation to see more about what caused the error.