nix-super/doc/manual/source/release-notes/rl-2.18.md

# Release 2.18 (2023-09-20)

- Two new builtin functions,
  [`builtins.parseFlakeRef`](@docroot@/language/builtins.md#builtins-parseFlakeRef)
  and
  [`builtins.flakeRefToString`](@docroot@/language/builtins.md#builtins-flakeRefToString),
  have been added.
  These functions are useful for converting between flake references encoded as attribute sets and URLs.

- [`builtins.toJSON`](@docroot@/language/builtins.md#builtins-parseFlakeRef) now prints [--show-trace](@docroot@/command-ref/conf-file.html#conf-show-trace) items for the path in which it finds an evaluation error.

- Error messages regarding malformed input to [`nix derivation add`](@docroot@/command-ref/new-cli/nix3-derivation-add.md) are now clearer and more detailed.

- The `discard-references` feature has been stabilized.
  This means that the
  [unsafeDiscardReferences](@docroot@/development/experimental-features.md#xp-feature-discard-references)
  attribute is no longer guarded by an experimental flag and can be used
  freely.

- The JSON output for derived paths which are store paths is now a string, not an object with a single `path` field.
  This only affects `nix-build --json` when "building" non-derivation things like fetched sources, which is a no-op.

- A new builtin [`outputOf`](@docroot@/language/builtins.md#builtins-outputOf) has been added.
  It is part of the [`dynamic-derivations`](@docroot@/development/experimental-features.md#xp-feature-dynamic-derivations) experimental feature.

- Flake follow paths at depths greater than 2 are now handled correctly, preventing "follows a non-existent input" errors.

- [`nix-store --query`](@docroot@/command-ref/nix-store/query.md) gained a new type of query: `--valid-derivers`. It returns all `.drv` files in the local store that *can be* used to build the output passed in argument. This is in contrast to `--deriver`, which returns the single `.drv` file that *was actually* used to build the output passed in argument. In case the output was substituted from a binary cache, this `.drv` file may only exist on said binary cache and not locally.
Release notes 2023-09-20 12:42:49 +03:00			`# Release 2.18 (2023-09-20)`

			`- Two new builtin functions,`
			[`builtins.parseFlakeRef`](@docroot@/language/builtins.md#builtins-parseFlakeRef)
			`and`
			[`builtins.flakeRefToString`](@docroot@/language/builtins.md#builtins-flakeRefToString),
			`have been added.`
			`These functions are useful for converting between flake references encoded as attribute sets and URLs.`

			- [`builtins.toJSON`](@docroot@/language/builtins.md#builtins-parseFlakeRef) now prints [--show-trace](@docroot@/command-ref/conf-file.html#conf-show-trace) items for the path in which it finds an evaluation error.

			- Error messages regarding malformed input to [`nix derivation add`](@docroot@/command-ref/new-cli/nix3-derivation-add.md) are now clearer and more detailed.

			- The `discard-references` feature has been stabilized.
			`This means that the`
manual: Contributing -> Development, Hacking -> Building (#9014) * manual: Contributing -> Development, Hacking -> Building what's currently called "hacking" are really instructions for setting up a development environment and compiling from source. we have a contribution guide in the repo (which rightly focuses on GitHub workflows), and the material in the manual is more about working on the code itself. since we'd otherwise have three headings that amount to "Building Nix", this change also moves the "classic Nix" instructions to the top. we may want to reorganise this in the future, and bring contributor-oriented information closer to the code, but for now let's stick to more accurate names to ease navigation. 2024-07-25 05:53:06 +03:00			`[unsafeDiscardReferences](@docroot@/development/experimental-features.md#xp-feature-discard-references)`
Release notes 2023-09-20 12:42:49 +03:00			`attribute is no longer guarded by an experimental flag and can be used`
			`freely.`

			- The JSON output for derived paths which are store paths is now a string, not an object with a single `path` field.
			This only affects `nix-build --json` when "building" non-derivation things like fetched sources, which is a no-op.

			- A new builtin [`outputOf`](@docroot@/language/builtins.md#builtins-outputOf) has been added.
manual: Contributing -> Development, Hacking -> Building (#9014) * manual: Contributing -> Development, Hacking -> Building what's currently called "hacking" are really instructions for setting up a development environment and compiling from source. we have a contribution guide in the repo (which rightly focuses on GitHub workflows), and the material in the manual is more about working on the code itself. since we'd otherwise have three headings that amount to "Building Nix", this change also moves the "classic Nix" instructions to the top. we may want to reorganise this in the future, and bring contributor-oriented information closer to the code, but for now let's stick to more accurate names to ease navigation. 2024-07-25 05:53:06 +03:00			It is part of the [`dynamic-derivations`](@docroot@/development/experimental-features.md#xp-feature-dynamic-derivations) experimental feature.
Release notes 2023-09-20 12:42:49 +03:00
			`- Flake follow paths at depths greater than 2 are now handled correctly, preventing "follows a non-existent input" errors.`

			- [`nix-store --query`](@docroot@/command-ref/nix-store/query.md) gained a new type of query: `--valid-derivers`. It returns all `.drv` files in the local store that can be used to build the output passed in argument. This is in contrast to `--deriver`, which returns the single `.drv` file that was actually used to build the output passed in argument. In case the output was substituted from a binary cache, this `.drv` file may only exist on said binary cache and not locally.