bug#36566: 27.0.50; debug is sometimes horribly slow

[Rudolf Schlatte]

Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of
text editors" <bug-gnu-emacs@gnu.org> writes:

>> The only issue is "oh no, not yet another printing variable" (that
>> people will be setting to 14 in ~/.emacs and then everything that does
>> `prin1' to write out data will fail).
>
> As someone requested long ago, we should have some way to "reset" the
> printing config context in a single step without having to mention
> individually each and every var.

Common Lisp uses with-standard-io-syntax for this purpose
(http://clhs.lisp.se/Body/m_w_std_.htm).