When configuring the built-in Rust evaluator by setting HK_PKL_BACKEND=pklr, deprecation warnings are emitted for the properties check_byte_order_marker and fix_byte_order_marker.

[pklr] WARNING: property 'check_byte_order_marker' is deprecated: Use `Builtins/byte_order_marker.pkl`
[pklr] WARNING: property 'fix_byte_order_marker' is deprecated: Use `Builtins/byte_order_marker.pkl`

Steps to Reproduce

hk.pkl file:

amends "package://github.com/jdx/hk/releases/download/v1.44.1/[email protected]#/Config.pkl"
import "package://github.com/jdx/hk/releases/download/v1.44.1/[email protected]#/Builtins.pkl"

local linters = new Mapping<String, Step> {
    ["stylua"] = Builtins.stylua
    ["action-lint"] = Builtins.actionlint
    ["mise"] = Builtins.mise
}

hooks {
    ["check"] {
        steps = linters
    }
    ["fix"] {
        fix = true
        steps = linters
    }
    ["pre-commit"] {
        fix = true
        stash = "git"
        steps = linters
    }
}

mise.toml file:

[env]
HK_PKL_BACKEND = "pklr"
HK_MISE = 1

[settings]
experimental = true

[tools]
actionlint = "latest"
hk = "latest"
pkl = "latest"
stylua = "latest"

1. Run hk install --mise

   ❯ hk install --mise
   [pklr] WARNING: property 'check_byte_order_marker' is deprecated: Use `Builtins/byte_order_marker.pkl`
   [pklr] WARNING: property 'fix_byte_order_marker' is deprecated: Use `Builtins/byte_order_marker.pkl`
   Installed hk hook via git config: hook.hk-pre-commit.command
   

Environment

mise: 2026.4.22 macos-arm64 (2026-04-25)
hk: 1.44.1
OS: macOS 26.4.1
Backend: pklr