Re: [PATCH] Automatically set `geiser-guile-load-path' from .dir-locals

[Christopher Lemmer Webber]

Miguel Ángel Arruga Vivas writes:

> Hi Maxim and Christopher,
>
> Maxim Cournoyer <maxim.cournoyer@gmail.com> writes:
>>[...]
>> Christopher Lemmer Webber <cwebber@dustycloud.org> writes:
>> [...]
>>> I figured out what was happening!  The bug is *technically* in vc-mode.
>>> However, nontheless it manifested here...
>>>
>>> Here's what happened.  vc-mode has some various hacks, as you can see
>>> above with "hack-local-variables-apply"... which traverses the dirlocals
>>> stuff.  (Not sure what the purpose is, didn't look too long.)
>
> The file where these functions are located is lisp/files.el, right on
> the Emacs core.  Some modes add hooks there, like flyspell or cc, but
> not vc, so I don't really think the problem is exclusive from that mode
> after some debugging.
>
> This code ends up in file-local-variables-alist, even though
> dir-local-variables-alist contains the correct values for some reason I
> still don't really understand.
>
>>> However for whatever reason, vc-mode also seems to be reusing buffers
>>> such as `*vc-diff*'... and somehow still is left in the directory
>>> context it *first* was used in.
>
> This may be the culprit but I think it isn't the issue, as
> file-local-variables-alist accumulates every eval marked as nil, not
> only the first/last one... when it fails, as we've seen.
>
>>> Thus if I C-x v = in a guix-oriented buffer first, and then switch to
>>> another completely different project and do the same, it's loading the
>>> dirlocals from Guix(...!!!!)
>>>
>>> This is clearly a bug in vc-mode, I'll try to report it as such.
>
>> Thank you for the investigation.  I'd be really happy if you could
>> report the problem upstream (M-x report-emacs-bug) aznd link to it here!
>
> I haven't reported it yet, but as you can see I have a reproducer script
> attached.  I haven't seen anything in vc-code that points in that
> direction, surely though Emacs people will have a better understanding.
>
> Christopher, would you mind to CC me if you open the bug?  I can do it
> too if you tell me to, but I don't want to create a duplicate entry if
> we do it roughly at the same time.

It sounds like you're already putting together the work to do it.  If
you don't mind doing it that would save me a lot of time right
now... I'm quite swamped!  I'd be very grateful!

>> [..] Miguel had written in IRC at the time of the initial report, but
>> to no avail.
>
> Maxim, could you test the script to check if we can narrow the cases?
> It shows the README in the emacs it opens, so it should be
> straight-forward.
>
>>> In the meanwhile, I used this hacky "fix".  Maybe worth applying for the
>>> moment... what do you think of it?
>>
>> I'd like to have the upstream bug linked in that fix rather than the
>> Guix one; that way it'll be possible to track upstream resolution and
>> know when the workaround can be removed.
>
> Apart from the tracking reference, I agree that it's worth applying it.
> And also, thank you both for making easier to work on guix. :-)

Okay cool; since you two have already basically reviewed this code I'll
just make the suggested change and push it to the master branch.  Thank
you!