[bug#52730] [PATCH] gnu: gst-plugins/selection: Make #:configure-flags optional.

[Jack Hill]

On Fri, 24 Dec 2021, Jack Hill wrote:

> On Fri, 24 Dec 2021, Liliana Marie Prikler wrote:
>
> > Hi,
> >
> > Am Dienstag, dem 21.12.2021 um 22:34 -0500 schrieb Jack Hill:
> > > * gnu/packages/gstreamer.scm (gst-plugins/selection): Provide the
> > > empyt list as a default value for #:configure-flags.
>
> > The current implementation ought to copy pre-existing configure-flags
> > as-is if you don't supply flags on your own.  I personally believe
> > that's preferable over an empty value, that will probably be reset.
> > WDYT?
>
> Yes, I agree that the current implementation ought to, but it doesn't. 
> Instead it complains:
>
> """
> ice-9/psyntax.scm:2794:12: In procedure syntax-violation:
> Syntax error:
> unknown location: quote: bad syntax in form quote
> """
>
> I'll see about a v2.

I've looked at it for a little bit now, but I'm afraid that I'm stuck. I 
tried setting the default to #f (which may have been happening implicitly 
anyway):

```
(define-public gst-plugins/selection
  (lambda* (pkg #:key plugins (configure-flags #f))
    "Build PKG with only PLUGINS enabled.  Optionally, if CONFIGURE-FLAGS are
given, also pass them to the build system instead of the ones used by PKG."
    (package/inherit pkg
      (arguments
       (substitute-keyword-arguments (package-arguments pkg)
         ((#:configure-flags flags `(,@(or configure-flags '())))
          `(append
            (list
             ,@(map (lambda (plugin)
                      (string-append "-D" plugin "=enabled"))
                    plugins))
            (list ,@(or configure-flags flags))))
          ((#:phases phases)
           `(modify-phases ,phases
              (add-after 'unpack 'disable-auto-plugins
                (lambda _
                  (substitute* "meson_options.txt"
                    (("'auto'") "'disabled'")))))))))))
```

but that still gives me the "bad syntax in form quote" message. I can keep 
thinking about it, but if someone else knows the solution, I'd be happy to 
learn from you :)

Best,
Jack