retitle 39805 describe-variable fails to print some circular list values
# describe-variable only fails starting from 26.1
notfound 39805 25.3
found 39805 26.1
tags 39805 + patch
quit

For the record, the pp-buffer call in the original report fails in Emacs
25 (and earlier, I assume), but the describe-variable case only fails
starting from 26.1, specifically commit 2c18969c81.

[1: 2c18969c81]: 2017-03-02 02:08:32 -0500
  * lisp/help-fns.el (describe-variable): Use cl-print for the value
  https://git.savannah.gnu.org/cgit/emacs.git/commit/?id=2c18969c810f338d73beda592ee5af7103132e97

Here is the patch intended for emacs-27: