Variable: bad-packages-alist

Alist of packages known to cause problems in this version of Emacs.
Each element has the form (PACKAGE SYMBOL REGEXP STRING).
PACKAGE is either a regular expression to match file names, or a
symbol (a feature name); see the documentation of
`after-load-alist', to which this variable adds functions.
SYMBOL is either the name of a string variable, or `t'. Upon
loading PACKAGE, if SYMBOL is t or matches REGEXP, display a
warning using STRING as the message.