stylix: guard home-manager-integration config

[Flameopathic]

Fixes #1492

Things done

• Tested locally
• Tested in testbed
• Commit message follows commit convention
• Fits style guide
• Respects license of any existing code used

Notify maintainers

@MattSturgeon

[MattSturgeon]

I'm not sure if it is acceptable practice to use lib.mkIf on an option default. I will revise as requested.

You can't do it as part of the option declaration, however you can do it by moving the default definition from options to config:

config.stylix.base16Scheme = lib.mkIf (...) (lib.mkOptionDefault (...));

That said, this doesn't solve the issue. With this approach you would get option `stylix.base16Scheme` used but not defined errors because the underlying issue isn't in the option's value, but the fact that its value is read when it shouldn't be.

See also #1492 (comment)

[Flameopathic]

CC @danth

[0xda157]

LGTM

[trueNAHO]

The patch LGTM.

@Keyruu and @paholg, could you test whether this PR resolves #1492?

For reference, I have successfully tested that this PR still evaluates my standalone Home Manager setup:

Tested-by: NAHO <90870942+trueNAHO@users.noreply.github.com>

I still feel like the correct thing to do is avoid evaluating stylix.base16Scheme when stylix.enable = false,¹ however IDK how big of a treewide cleanup this will be. Such a change would (of course) be easier if we added a regression test.

-- #1492 (comment)

Yes, improving the test suite is a slow but ongoing process 1 2. Although this part of the codebase could indeed be polished, this is surprisingly low priority and should probably just continue receiving hotfixes for the foreseeable future, until it inevitably needs to be rewritten to continue making progress on other more "important" tasks.

Footnotes

1. Ideally, none of stylix's option values would be evaluated when stylix.enable = false ↩

[MattSturgeon]

Ideally, none of stylix's option values would be evaluated when stylix.enable = false

If so, then this PR doesn't fully address the issue. Changing a default is not sufficient to ensure stylix.enable = false always disables the feature.

[0xda157]

Ideally, none of stylix's option values would be evaluated when stylix.enable = false

In that case config should be guarded by mkIf config.stylix.enable

[trueNAHO]

LGTM. Let's wait a bit if the bug reporters also test this PR.

[trueNAHO]

I managed to get my [previous] configuration to work with the Stylix revision in the pull request by importing the home-manager module via home-manager.sharedModules, as suggested, and removing the global module.

-- alex-massa, #1492 (comment)

This PR has been successfully tested by alex-massa:

Tested-by: https://github.com/alex-massa

Let's wait a bit if the bug reporters also test this PR.

I suggest merging this PR on Monday if the bug reporters have still not replied until then, giving them 7 days to reply. For reference, #1492 has been open for two weeks and has currently 7 upvotes.

[Flameopathic]

I have slightly updated documentation to reflect this change.

[stylix-automation]

Successfully created backport PR for release-25.05:

• [release-25.05] stylix: guard home-manager-integration config #1564