Subject: bug#10232: 24.0.92; gnus-summary-scroll-up error

From: Stefan Monnier <[email-masked]>
Date: Tue, 06 Dec 2011 09:20:22 -0500

> Debugger entered--Lisp error: (error "Invalid byte code in /usr/local/share/emacs/24.0.92/lisp/wid-edit.elc")

You've rebuilt wid-edit.elc after the current process had already
loaded it.  Either restart your Emacs, or just do
M-x load-library RET wid-edit RET

The wid-edit.el file uses `byte-compile-dynamic' which means that when
you read wid-edit.elc some parts are skipped and replaced by references
to the corresponding chunk in the file.  Those chunks are later fetched
on demand, but of course, if the file gets modified in the mean time you
can get into trouble.
The same trick is used to autoload docstrings, but luckily in the case
of docstrings the code happens to detect the problem at a stage early
enough that we can usually fix it (update the references and try again)
without user intervention.
For the bytecode refs used with `byte-compile-dynamic' by the time we
discover the problem, we just have the file name (shown in the error
message) but not the object that refers to it, so we can't do the fix
up :-(

        Stefan