fix(crash): unhook signal to avoid double widget destruction

[Geobert]

Summary

When hitting Return or Escape when completion list is visible, both _lib_tagging_tag_destroy hooked by

darktable/src/libs/tagging.c

Line 3973 in 733a441

g_signal_connect(entry, "focus-out-event",

and

darktable/src/libs/tagging.c

Line 3876 in 733a441

gtk_widget_destroy(d->floating_tag_window);

boith got called and destroys twice the floating window

unhook the signal on Return and Escape to avoid that

• fix in the flake.nix to allow build on NixOS unstable

• fix in the build.sh to be compatible with more Linux distrib (NixOS)

Referenced issue

Fixes #20919

Checklist

• I have read CONTRIBUTING.md and the
  coding style.
• The pull request is one logical change, and every commit compiles on its
  own.
• I ran the relevant tests: unit tests, src/tests/integration/ where the
  pixelpipe is touched, or darktable-cli as a headless smoke test.
• New user-visible strings use _(), new preferences are registered in
  data/darktableconfig.xml.in.
• A RELEASE_NOTES.md entry was added.

Test instructions

Was crashing with the procedure described in #20919 and not crashing anymore

AI assistance

None

[Geobert]

I can’t see what’s wrong in the checks that didn’t pass :-/

[zisoft]

/Users/runner/work/darktable/darktable/src/src/libs/tagging.c:3862:7: fatal error: label followed by a declaration is a C23 extension [-Wc23-extensions]
 3862 |       GtkWidget *entry = dt_gui_get_widget(controller);
      |       ^
1 error generated.

You cannot declare a local variable inside the case block of a switch statement.
Move the variable declaration GtkWidget *entry = NULL; before the switch.

[Geobert]

Thanks! I did a search on error and it didn’t show up, I guess I need to download the whole log

[zisoft]

search for error: (with the colon) in the logs.

[TurboGit]

Please separate the different changes on separate commits. The PR is about signal and this is only covered by changes in tagging.c.

[TurboGit]

Looks good to me, thanks!

[TurboGit]

@Geobert : I'll see if I can rebase from GitHub, but please remember to never merge master into your topic branch. The policy on Darktable is to rebase when needed.

[Geobert]

I though I did a rebase… After all these years as a dev, I still suck at git x)

[TurboGit]

Manually merged with conflict resolution.