If you use Emacs 23 and
ido, and you see this
error when you run
Error in post-command-hook: (wrong-type-argument sequencep t)
…you might have an outdated version of
ido.el. You probably have version
1.56, from 2002, which is included in many Emacs packages. Details on the bug in
this emacs.bugs thread.
Happily, the bug is fixed in the
2009 version of ido.el.
Take a look at your Emacs package and see if it has that version, maybe in
/usr/share/emacs/23.1/site-lisp or somewhere similar. If not, grab it and put
it somewhere in your path so that it takes precedence over your package’s old
version. Happy editing!