Config-tethered installations ignore apps-dir

[LiberalArtist]

What version of Racket are you using?
Racket v8.3 [cs]

What program did you run?
I've put an example at https://gist.github.com/LiberalArtist/f96fa9fab28c9122631f0d3b1d4f9123.

What should have happened?
The drracket.desktop file should have been installed into the configured apps-dir.

Please include any other relevant details
I believe the apps-dir only applies on (non-Mac) Unix-like systems. I tried this on Kubuntu 21.10. The same issue affects Guix's racket package.

[mflatt]

Currently, .desktop file creation is specifically skipped in tethering mode.

After refreshing my memory on how this all works, it looks like the consistent approach would be to add 'addon-tethered-app-dir and 'config-tethered-app-dir for use in a tethered setups. The latter could just be 'app-dir, since 'app-dir is otherwise unused in the same way that 'bin-dir and 'gui-bin-dir are not used for installation layering, but I'd be inclined to use 'config-tethered-app-dir for consistency.

Does that sound right to you?

[mflatt]

That idea seems to work out, at least in my experiments so far. I've pushed the change, partly with the idea that a round of snapshots will make it easier to try more experiments.

[LiberalArtist]

This seems to work!

When I'd looked at this before, I vaguely remember having been unsure why 'app-dir had been handled differently than other keys. But adding 'config-tethered-app-dir analogously to the 'bin-dir case seems like a fine solution; at least, I can't remember any downside.

I will send a patch to Guix in the hope of getting more people to try 11ccee3 and ece8b17 before the 8.4 release.

[LiberalArtist]

Submitted to Guix as https://issues.guix.gnu.org/53020.