GNU bug report logs - #45619
No warning when pcase-let is binding dynamic variable

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Message #41 received at 45619 <at> debbugs.gnu.org (full text, mbox):

From: Lars Ingebrigtsen <larsi <at> gnus.org>
To: Michael Heerdegen <michael_heerdegen <at> web.de>
Cc: jixiuf <jixiuf <at> qq.com>, 45619 <at> debbugs.gnu.org,
 Stefan Monnier <monnier <at> iro.umontreal.ca>
Subject: Re: bug#45619: 28.0.50; pcase-let on MacOS doesn't work
Date: Sat, 12 Feb 2022 08:46:02 +0100

Michael Heerdegen <michael_heerdegen <at> web.de> writes:

>> (pcase-let ((`(,default-directory) '( "/tmp/")))
>>     (call-interactively 'find-file))
>>
>> Expected behavior: Find file in "/tmp/"
>> Observed behavior: Find file in "~"
>
> AFAICT the issue here is that `pcase-let' always creates lexically
> scoped bindings, even for special variables.  That can be surprising.
>
> @Stefan, what can we do?  Document better?  Add compiler warnings?  Or
> is it possible to "fix" this?

I tried the form in Emacs 29, and I got the expected behaviour here.  So
was this fixed since this bug was reported?  (But I only tested on Debian.)

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

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