Tested commit d8c9abc and it does seem to fix #1124 for me.

@tweag/topiary-core-team we'll need to cut a release for this fix so that 0.7.x is again forwards compatible

Is there anything that's needed to make this PR land on main? Can I help in any way?

Hi @Niols I was on vacation so the release was a bit delayed. I should have it out for review tomorrow.

Oh. Sorry, I didn't want to put pressure on your vacation or anything! I was just curious why the PR wasn't on main (I rely on the flake myself).

This has the effect of making all of languages overridden whenever one defines just another language. That is, if the configuration is merged with a custom configuration of the form languages.mybar = {..}, all prebuilt languages will be wiped out, and only mybar will remain. Is that the expected behavior?

This has the effect of making all of languages overridden whenever one defines just another language. That is, if the configuration is merged with a custom configuration of the form languages.mybar = {..}, all prebuilt languages will be wiped out, and only mybar will remain. Is that the expected behavior?

@yannham I'm assuming the built-in values should have the lowest merge priority individually, to your point though we should have every language field have its own default value.

Nice catch!

@yannham Thanks again for the per language default observation, I confirmed that the approach does indeed behave as desired.

I now get

$ topiary format -M -C .topiary.ncl lib/name.ml
[2025-11-25T17:31:57Z ERROR topiary::error] Nickel error: Other(
        "missing field `extensions`",
    )

when trying my usual configuration

{
	languages = {
		bash.indent | priority 1 = "	",
		css.indent | priority 1 = "	",
		json.indent | priority 1 = "	",
		nickel.indent | priority 1 = "	",
		ocaml.indent | priority 1 = "	",
		ocaml_interface.indent | priority 1 = "	",
		ocamllex.indent | priority 1 = "	",
		rust.indent | priority 1 = "	",
		toml.indent | priority 1 = "	",
	},
}

Reverting nixpkgs to 1r3cbzi0zgfcw1mjl8piss4xbhwmwpd3l22pjjc0hlvrpsrs73f8, the commit before 0.7.1 was merged, works. Am I missing something about how this is now set up? This doesn’t seem like a minor change.

Hmm oh boy, looks like the fix broker the other things. @toastal the config above reproduces the issue I take it?

@mkatychev … yeah, my Nickel is a bit rusty at this point, but maybe something isn’t squaring right for me

Thanks for bringing this up, I'll look into it first thing tomorrow