bug#57790: Strange behavior with emacs-build-system

[Fredrik Salomonsson]

Fredrik Salomonsson <plattfot@posteo.net> writes:

> Hi,
>
> zimoun <zimon.toutoune@gmail.com> writes:
>
>> On Wed, 14 Sep 2022 at 02:59, Fredrik Salomonsson <plattfot@posteo.net> 
>> wrote:
>>
>>> If I name the local clone `issue.el` (name of the directory);
>>> `guix build -f guix.scm` will fail. It will just copy the file
>>> `issue.el` and then `ert-runner` fails as there is no test directory.
>>>
>>> But if I name the local clone something else, e.g. `issue-el` then it
>>> will copy all the files, `ert-runner` will be happy and
>>> `guix build -f guix.scm` will succeed.
>>>
>>> I'm not sure if this is an issue in `emacs-build-system`, `local-file`
>>> or plain old user error.
>>
>> Well, I guess it comes from ’unpack’; which reads:
>>
>> --8<---------------cut here---------------start------------->8---
>> (define* (unpack #:key source #:allow-other-keys)
>>   "Unpack SOURCE into the build directory.  SOURCE may be a compressed
>> archive, a directory, or an Emacs Lisp file."
>>   (if (string-suffix? ".el" source)
>>       (begin
>>         (mkdir "source")
>>         (chdir "source")
>>         (copy-file source (store-file->elisp-source-file source))
>>         #t)
>>       (gnu:unpack #:source source)))
>> --8<---------------cut here---------------end--------------->8---
>
> Ah, yeah that would make sense.
>
>> Well, I guess again that the ’source’ should contain something like,
>>
>>     (file-name (git-file-name name version)
>>
>> to avoid the issue.  But the naive approach does not work with
>> ’local-file’.
>
> Would `file-is-directory?` work? E.g.
>
>   (if (and (string-suffix? ".el" source)
>            (not (file-is-directory? source)))
>   …)
>
> I'm currently at work so I cannot test this right now.

I just tested it and it at least fixed my issue. I haven't tested any
other emacs package yet. Also I'm not sure if this is the best solution.
But we now know it is the `unpack` phase that is the cause.

-- 
s/Fred[re]+i[ck]+/Fredrik/g