Re: Splitting mkvtoolnix outputs: cycle detected in the references

["Ludovic Courtès" <ludo@gnu.org>]

Hi,

Pierre Neidhardt <mail@ambrevar.xyz> skribis:

> I'm trying to split mkvtoolnix-gui (depends on Qt) to a separate "gui" output.
> "out" would only contain the command line tools.
>
> Disabling Qt shrinks the closure size from 1.5+ GB to 277 MB.  Pretty
> neat, huh? :)

Yup!

> I naively tried to move mkvtoolnix-gui to the "gui" output:
>
> (add-after 'install 'post-install
>            (lambda* (#:key outputs #:allow-other-keys)
>              ;; Move the Qt interface to "gui".
>              (let ((out (assoc-ref outputs "out"))
>                    (gui (assoc-ref outputs "gui")))
>                (mkdir-p (string-append gui "/bin"))
>                (rename-file (string-append out "/bin/mkvtoolnix-gui")
>                             (string-append gui "/bin/mkvtoolnix-gui")))
>              #t))
>
>
> But I get the following error after the
> `compress-documentation' phase:
>
> cycle detected in the references of `/gnu/store/7asc0q7kik1ak463nj8g675hnab7h982-mkvtoolnix-31.0.0-gui'
>
> It's unclear to me why there would be a cycle.  Any clue how to
> investigate from there?

This error means that the two outputs, “out” and “gui”, refer to each
other; the daemon does not support that.

To find out where the references come from, you can build with -K, and
then grep -r for one output in the other.

If it turns out to be impossible to remove the cycle, I’d suggest making
a separate package for the GUI.

HTH!

Ludo’.