I'm played around with my .emacs and installed a few packages from melpa related to C++. Now when I start emacs, I get this error
eval-buffer: Symbol's function definition is void: eieio-defclass-autoload
It doesn't happen with emacs -Q. So I completely emptied my .emacs and removed all packages I installed today. The error persists. I also use desktop sessions, so I turned this off with emacs --no-desktop but with no success. Which file is loaded that causes the error? Here is the complete *messages* buffer
Loading 00debian-vars...done Loading /etc/emacs/site-start.d/50auctex.el (source)... Loading /usr/share/emacs/site-lisp/auctex.el (source)...done Loading /usr/share/emacs/site-lisp/preview-latex.el (source)...done Loading /etc/emacs/site-start.d/50auctex.el (source)...done Loading /etc/emacs/site-start.d/50autoconf.el (source)...done Loading /etc/emacs/site-start.d/50cmake-data.el (source)...done Loading /etc/emacs/site-start.d/50dictionaries-common.el (source)... Loading /var/cache/dictionaries-common/emacsen-ispell-dicts.el (source)... Error while loading 50dictionaries-common: Symbol's value as variable is void: debian-aspell-only-dictionary-alist Loading /etc/emacs/site-start.d/50ess.el (source)...done Loading /etc/emacs/site-start.d/50global.el (source)...done Loading /etc/emacs/site-start.d/50python-docutils.el (source)...done eval-buffer: Symbol's function definition is void: eieio-defclass-autoload
So I realized that eieio is part of cedet but didn't know how to get rid of it I guess since it's now included into emacs.
--debu-initwhen starting Emacs? This would give you the stack-trace for this problem. EIEIO is the object system, used by many packages other than CEDET (although it's part of the package). It would be difficult to guess who's doing that. the reason someone would be looking for this variable would be a definition s.a.(defclass ...). Another way to identify the problem would be to try to byte-compile the *.el files that are being loaded.