# 2026-01-05

 - Deprecated `mkSubmoduleOptions`. Declare options directly instead, e.g.
   `options.flake.foo = mkOption { ... }`. This works since Nixpkgs 22.05.

 - Deprecated `mkDeferredModuleType` and `mkDeferredModuleOption`. Use
   `mkPerSystemType` and `mkPerSystemOption` respectively for `perSystem`
   type-merging. For other uses, use Nixpkgs' `types.deferredModuleWith`.

   Note: flake-parts' implementation returns a list on merge, whereas Nixpkgs'
   returns a single module. Add `apply = m: [ m ];` to your option if you need
   the list behavior.

# 2024-05-16

 - **Breaking**: Minimum supported Nixpkgs lib version is now 23.05 (was 22.05),
   due to the use of the `class` argument in `evalModules`.

 - Add `class` to `evalModules` calls for imports "type checking".

# 2023-05-30

 - Fix a strictness issue in `perInput`, affecting `inputs'`, `self'`.
   This has caused infinite recursions and potentially performance issues since
   the introduction of these module arguments.

# 2023-05-08

 - Add [`importApply`](https://flake.parts/define-module-in-separate-file.html?highlight=importApply#importApply) for bringing variables from the flake scope into module files.

 - Add `mkDeferredModuleOption` as a generic name for the implementation of `mkPerSystemOption`.

# 2023-03-26

 - Add preliminary support for `disabledModules` for modules exposed via the importable `flakeModules` module.
   This requires a Nixpkgs of 2023-03-09 or newer.

# 2023-01-05

 - Add importable `easyOverlay` module for defining an overlay "easily" by reusing `perSystem`.
   This is not for consuming overlays.

# 2022-12-25

 - Added a new `flake.flakeModules` option so a flake can expose a module
   to be used in a downstream flake's flake-parts usage. `.flakeModule` is
   now an alias for `.flakeModules.default`.

   Option only available if `flake-parts.flakeModules.flakeModules` is imported.

# 2022-12-17

 - The old syntax `mkFlake { inherit self; }` is now strongly discouraged in
 favor of:

   ```nix
   outputs = inputs@{ flake-parts, ... }:
     flake-parts.lib.mkFlake { inherit inputs; } { /* module */ }
   ```

   This fixes an infinite recursion that occurs with the old syntax when
   using the `inputs` module argument in `imports`.

   If you're under the impression that this already worked, that's probably
   because you were using `inputs` from the lexical scope (ie directly from
   the flake outputs function arguments), rather than in a separate module file.


# 2022-12-07

 - The `darwinModules` option has been removed. This was added in the early days
   without full consideration. The removal will have no effect on most flakes
   considering that the [`flake` option](https://flake.parts/options/flake-parts.html#opt-flake)
   allows any attribute to be set. This attribute and related attributes should
   be added to the nix-darwin project instead.

# 2022-10-11

 - The `nixpkgs` input has been renamed to `nixpkgs-lib` to signify that the
   only dependency is on the `lib` attribute, which can be provided by either
   the `nixpkgs?dir=lib` subflake or by the `nixpkgs` flake itself.

 - The templates now use the default, _fixed_ `nixpkgs?dir=lib` dependency instead
   of a _following_ `nixpkgs` dependency.

# 2022-05-25

 - `perSystem` is not a `functionTo submodule` anymore, but a `deferredModule`,
    which is a lot like a regular submodule, but possible to invoke multiple
    times, for each `system`.

    All `perSystem` value definitions must remove the `system: ` argument.
    If you need `system` to be in scope, use the one in the module arguments.

    ```diff
    -perSystem = system: { config, lib, ... }:
    +perSystem = { config, lib, system, ... }:
    ```

    All `perSystem` option declarations must now use `flake-parts-lib.mkPerSystemOption`.

    ```nix
    {
      options.perSystem = mkPerSystemOption ({ config, ... }: {
        options = {
          # ...
        };
        # ...
      });
    }
    ```

 - `flake-modules-core` is now called `flake-parts`.

 - `flake.overlay` has been removed in favor of `flake.overlays.default`.