bug#81223: [PATCH] Fix file-missing error during async native compilation

On 2026-07-29 11:18, James Cherti wrote:
> Hello Andrea,
> 
> It makes sense. I've updated the patch:
> 
> Attached: 0001-V2-Fix-file-missing-error-during-async-native- 
> compilati.patch
> 
> On 2026-07-27 11:21, Andrea Corallo wrote:
>> James Cherti <[email protected]> writes:
>>
>>> On 2026-06-11 11:07, Sean Whitton wrote:
>>>> James Cherti [11/Jun  9:41am -04] wrote:
>>>>>   From a8f13a55a4838a0d2ead62513c7d1a9616c1b501 Mon Sep 17 00:00:00 
>>>>> 2001
>>>>> From: James Cherti <[email protected]>
>>>>> Date: Thu, 11 Jun 2026 09:29:39 -0400
>>>>> Subject: [PATCH] Fix file-missing error during async native 
>>>>> compilation
>>>>>
>>>>> When a package is upgraded or deleted, the async compilation queue can
>>>>> retain stale jobs for files that no longer exist on disk.  
>>>>> Attempting to
>>>>> resolve the target .eln filename for these missing files signals a
>>>>> file-missing error that disrupts the queue.
>>>>>
>>>>> * lisp/emacs-lisp/comp-run.el (comp--run-async-workers): Verify source
>>>>> files exist before attempting to resolve their .eln paths in both the
>>>>> dispatch loop and the process sentinel.
>>>>
>>>> Shorten these remarks and add corresponding code comments, please.
>>>>
>>>> Adding Philip for review since it seems primarily a package.el issue.
>>>
>>> You can find attached v2 of the patch
>>> (0001-V2-Fix-file-missing-error-during-async-native-compilati.patch).

Let me know if you have feedback on v2 or if this is ready to merge.

>>>
>>> Changes since the previous version:
>>> - Added explanatory comments regarding the file existence checks.
>>>
>>> For context, I want to clarify that this fix is not specifically tied
>>> to package management operations. It resolves a broader issue by
>>> handling any stale jobs in the async native compilation queue where
>>> the target files no longer exist on disk.
>>>
>>> -- 
>>> James Cherti
>>
>> Hi James,
>>
>> Thanks for the patch. Couple of points:
>>
>>> GitHub: https://github.com/jamescherti
>>> Website: https://www.jamescherti.com/
>>>
>>>  From 55ba77809cb1d371f79eb4e59df8db819e100456 Mon Sep 17 00:00:00 2001
>>> From: James Cherti <[email protected]>
>>> Date: Fri, 12 Jun 2026 06:07:23 -0400
>>> Subject: [PATCH] Fix file-missing error during async native compilation
>>>
>>> The async native compilation queue can sometimes retain stale jobs for
>>> files that no longer exist on disk (for example, when files are removed
>>> during a package upgrade or deletion). Attempting to resolve the target
>>> .eln filename for these missing files signals a file-missing error.
>>>
>>> * lisp/emacs-lisp/comp-run.el (comp--run-async-workers): Verify source
>>> files exist before attempting to resolve their .eln paths in both the
>>> dispatch loop and the process sentinel.
>>> ---
>>>   lisp/emacs-lisp/comp-run.el | 23 ++++++++++++++++++-----
>>>   1 file changed, 18 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/lisp/emacs-lisp/comp-run.el b/lisp/emacs-lisp/comp-run.el
>>> index 64e20327906..c70c5b0a512 100644
>>> --- a/lisp/emacs-lisp/comp-run.el
>>> +++ b/lisp/emacs-lisp/comp-run.el
>>> @@ -282,13 +282,20 @@ comp--run-async-workers
>>>            when (or native-comp-always-compile
>>>                     load ; Always compile when the compilation is
>>>                          ; commanded for late load.
>>>                     ;; Skip compilation if `comp-el-to-eln-filename' 
>>> fails
>>>                     ;; to find a writable directory.
>>> -                  (with-demoted-errors "Async compilation :%S"
>>> -                    (file-newer-than-file-p
>>> -                     source-file (comp-el-to-eln-filename source- 
>>> file))))
>>> +                  (and
>>> +                   ;; Verify that the source file still exists on disk
>>> +                   ;; as a regular file before calling
>>> +                   ;; `comp-el-to-eln-filename'. This check prevents
>>> +                   ;; `file-missing' errors caused by stale jobs in the
>>> +                   ;; async compilation queue.
>>> +                   (file-regular-p source-file)
>>> +                   (with-demoted-errors "Async compilation :%S"
>>> +                     (file-newer-than-file-p
>>> +                      source-file (comp-el-to-eln-filename source- 
>>> file)))))
>>
>> The file-regular-p check in the dispatch loop is currently bypassed when
>> either native-comp-always-compile or load is non-nil. Thus, stale jobs
>> in those modes still start a worker. Should the check wrap the entire or
>> condition?
>>> Also, the sentinel still has a check-then-use race: the source can
>> disappear between file-regular-p and comp-el-to-eln-filename, causing
>> the sentinel to signal before restarting the queue.
>>
>> I'm wondering, wouldn't maybe be safer to handle file-missing around
>> comp-el-to-eln-filename directly and ensure comp--run-async-workers is
>> always called? > Thanks
>>
>>    Andrea
>>
>>
>>
> 
> 
> -- 
> James Cherti
> GitHub: https://github.com/jamescherti
> Website: https://www.jamescherti.com/

--
James Cherti
GitHub: https://github.com/jamescherti
Website: https://www.jamescherti.com/