bug#52316: Package example from cookbook has bugs

[zimoun]

Hi Maxime,

On Sun, 05 Dec 2021 at 19:18, Maxime Devos <maximedevos@telenet.be> wrote:

> The example at
> https://guix.gnu.org/cookbook/en/html_node/Extended-example.html has
> two bugs:
>
> #:tests? is unconditionally set to #true. This is bad for cross-
> compilation and --without-tests=PACKAGE reasons, and would be flagged
> by the linter.

For cross-compilation, yes.  For ’--without-tests’, it is not an issue,
IMHO, or why is it?

> In the new 'check' phase, libgit2_clar is invoked unconditionally. This
> would be flagged by the linter.

Since it is an example showing non-trivial things, maybe it can be
pedagogical to have something half good, if and only if, “guix lint”
reports the half bad.  And add an explanation.  WDYT?


> Also, not exactly a bug, but still bad practice: the web page suggests:
>
> #:make-flags (list (string-append "prefix=" (assoc-ref %outputs "out"))
>                    "CC=gcc")
>
> however, hardcoding gcc is bad for cross-compilation reasons. It should
> use (cc-for-target) instead.

I agree.

Cheers,
simon