From: Evgenii Klimov via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
To: Eli Zaretskii <eliz@gnu.org>
Cc: kobarity <kobarity@gmail.com>, 72849@debbugs.gnu.org
Subject: bug#72849: [PATCH] Keep project's exec-path during with-temp-buffer call
Date: Thu, 29 Aug 2024 23:51:29 +0100 [thread overview]
Message-ID: <87ed677xji.fsf@lipklim.org> (raw)
In-Reply-To: <86y14ghmm1.fsf@gnu.org> (Eli Zaretskii's message of "Wed, 28 Aug 2024 15:12:54 +0300")
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Eli Zaretskii <eliz@gnu.org> writes:
>> Date: Wed, 28 Aug 2024 00:13:25 +0100
>> From: Evgenii Klimov via "Bug reports for GNU Emacs,
>> the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
>>
>> `with-temp-buffer' doesn't respect buffer-local environment variables,
>> `exec-path' in this case. Which results in executables not being found,
>> or the wrong versions of executables being picked up. E.g. if
>> environment variable is modified via .dir-local file or direnv/envrc
>> package.
>
> Hmm, this doesn't look clean to me: exec-path is just one variable,
> what makes it special here?
>
> Moreover, it sounds like python-shell-with-environment, which
> python-shell-prompt-detect calls, already attempts to have
> buffer-local value of exec-path to be available to Python, so why
> isn't that working for you? And if it isn't work, I think we should
> amend python-shell-with-environment to do this, so we don't need to do
> it "by hand".
Indeed, my initial approach is too manual.
Here the problem that I have: I don't use Python's "venv" module to
create virtual environment for the project. Instead, I use GNU Guix's
"guix shell" command [1] which provides augmented PATH and PYTHONPATH,
etc. to link project's dependencies. Then, envrc.el package picks up
these environment variables and makes them buffer-local project-wise
(`exec-path' and `process-environment').
You are correct that `python-shell-with-environment' provides
buffer-local variables, but `with-temp-buffer' treats `exec-path' and
`process-environment' variables very specially.
I didn't find this behavior in documentation, but look at this example:
(setq-default exec-path (list "global" "list"))
(setq-local exec-path (cons "local"
(default-value 'exec-path)))
(setq-default myvar (list "global" "list"))
(setq-local myvar (cons "local" (default-value 'myvar)))
(let ((exec-path exec-path) ; takes buffer-local
(myvar myvar)) ; takes buffer-local
(with-temp-buffer
(insert (car exec-path) ; uses global
"\n"
(car myvar)) ; uses `let'-binded
(buffer-string)))
;; => "global
;; local"
(require 'cl-lib)
(let ((myvar myvar))
;; temporarily binds buffer-local value to global symbol
(cl-letf (((default-value 'exec-path) exec-path))
(with-temp-buffer
;; global variable is used, but it's value is temporarily equal
;; to buffer-local value
(insert (car exec-path)
"\n"
(car myvar))
(buffer-string))))
;; => "local
;; local"
It's a simplified and expanded version of
`python-shell-with-environment' and `python-shell-prompt-detect'. As
you can see, `exec-path' is treated differently inside of
`with-temp-buffer' and `cl-letf' is needed to force `with-temp-buffer'
to use buffer-local value of `exec-path'.
In the new patch attached I show how this can be overcome. Don't know
if you'll consider my use case too narrow and specific, but I'll be glad
to hear your thoughts on this.
[1] https://guix.gnu.org/en/manual/en/guix.html#Invoking-guix-environment
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From 6db90f6087d0d3270e1d7a7d77d8830eac1f0154 Mon Sep 17 00:00:00 2001
From: Evgenii Klimov <eugene.dev@lipklim.org>
Date: Thu, 29 Aug 2024 23:36:12 +0100
Subject: [PATCH] Make python-shell--with-environment respect buffer-local
variables
* lisp/progmodes/python.el (python-shell--with-environment): Make
`with-temp-buffer' respect buffer-local values of
`process-environment' and `exec-path', if set.
---
lisp/progmodes/python.el | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index 7193cc19425..3e543442dba 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -3030,11 +3030,11 @@ (defun python-shell--with-environment (extraenv bodyfun)
(tramp-dissect-file-name default-directory 'noexpand)))))
(if vec
(python-shell--tramp-with-environment vec extraenv bodyfun)
- (let ((process-environment
- (append extraenv process-environment))
- (exec-path
- ;; FIXME: This is still Python-specific.
- (python-shell-calculate-exec-path)))
+ (cl-letf (((default-value 'process-environment)
+ (append extraenv process-environment))
+ ((default-value 'exec-path)
+ ;; FIXME: This is still Python-specific.
+ (python-shell-calculate-exec-path)))
(funcall bodyfun)))))
(defun python-shell--tramp-with-environment (vec extraenv bodyfun)
--
2.45.2
next prev parent reply other threads:[~2024-08-29 22:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-27 23:13 bug#72849: [PATCH] Keep project's exec-path during with-temp-buffer call Evgenii Klimov via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-08-28 7:12 ` Michael Albinus via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-08-28 12:12 ` Eli Zaretskii
2024-08-29 16:08 ` kobarity
2024-08-29 16:25 ` Eli Zaretskii
2024-08-29 22:51 ` Evgenii Klimov via Bug reports for GNU Emacs, the Swiss army knife of text editors [this message]
2024-08-30 14:43 ` kobarity
2024-08-31 10:17 ` Eli Zaretskii
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