Add CHANGELOG and crate READMEs

- Add CHANGELOG.md documenting 0.1.0 and 0.2.0 releases with contributor
  credits and PR links
- Add README.md to each crate linking to the changelog
- Link READMEs in Cargo.toml files
- Add repository field to -sys crates that were missing it
- Update top-level README to reference changelog and reflect -sys crate split
- Document changelog update step in release process

CHANGELOG.md

@@ -0,0 +1,83 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [0.2.0] - 2026-01-13
+
+### Added
+
+- Workaround for automatic C library input propagation in downstream Nix builds. ([#27] by [@roberth])
+- `EvalStateBuilder::load_ambient_settings()` to control whether global Nix settings are loaded. ([#36] by [@roberth])
+
+### Fixed
+
+- Path coercion failing with "path does not exist" errors due to missing `eval_state_builder_load()` call. ([#36] by [@aanderse])
+
+### Changed
+
+- Split `nix-bindings-util-sys` (which contained all low-level FFI bindings) into separate per-library `*-sys` crates. ([#27] by [@Ericson2314])
+  This allows downstream crates to depend on just the low-level bindings they need without pulling in higher-level crates.
+
+## [0.1.0] - 2026-01-12
+
+Initial release, extracted from the [nixops4 repository](https://github.com/nixops4/nixops4).
+
+### Added
+
+- `nix-bindings-store`: Rust bindings for Nix store operations
+  - Store opening (auto, from URI, from environment)
+  - Store path parsing and manipulation
+  - `Store::get_fs_closure` ([#12] by [@RossComputerGuy], [@roberth])
+  - `Clone` for `Derivation` ([#25] by [@Ericson2314])
+  - Store deduplication workaround for [nix#11979]
+  - aarch64 ABI support ([#26] by [@RossComputerGuy])
+- `nix-bindings-expr`: Rust bindings for Nix expression evaluation
+  - `EvalState` for evaluating Nix expressions
+  - Value creation (int, string, attrs, thunks, primops, etc.)
+  - Value inspection/extraction (`require_*` functions)
+  - Attribute selection and manipulation
+  - Thread registration for GC safety
+- `nix-bindings-fetchers`: Rust bindings for Nix fetchers
+- `nix-bindings-flake`: Rust bindings for Nix flake operations
+  - Flake locking
+  - Flake overriding
+- `nix-bindings-util`: Shared utilities
+  - Context management for Nix C API error handling
+  - Settings access
+- `nix-bindings-util-sys`: Low-level FFI bindings for all Nix C libraries
+
+### Contributors
+
+Thanks to everyone who contributed to the initial development, some of whom may not be listed with individual changes above:
+
+- [@aanderse]
+- [@Ericson2314]
+- [@ErinvanderVeen]
+- [@numinit]
+- [@prednaz]
+- [@Radvendii]
+- [@roberth]
+- [@RossComputerGuy]
+
+<!-- end of 0.1.0 release section -->
+
+[@aanderse]: https://github.com/aanderse
+[@Ericson2314]: https://github.com/Ericson2314
+[@ErinvanderVeen]: https://github.com/ErinvanderVeen
+[@numinit]: https://github.com/numinit
+[@prednaz]: https://github.com/prednaz
+[@Radvendii]: https://github.com/Radvendii
+[@roberth]: https://github.com/roberth
+[@RossComputerGuy]: https://github.com/RossComputerGuy
+
+[#12]: https://github.com/nixops4/nix-bindings-rust/pull/12
+[#25]: https://github.com/nixops4/nix-bindings-rust/pull/25
+[#26]: https://github.com/nixops4/nix-bindings-rust/pull/26
+[#27]: https://github.com/nixops4/nix-bindings-rust/pull/27
+[#36]: https://github.com/nixops4/nix-bindings-rust/pull/36
+[0.2.0]: https://github.com/nixops4/nix-bindings-rust/compare/0.1.0...0.2.0
+[0.1.0]: https://github.com/nixops4/nix-bindings-rust/releases/tag/0.1.0
+[nix#11979]: https://github.com/NixOS/nix/issues/11979

README.md

@@ -12,7 +12,7 @@ This workspace provides multiple crates that wrap different layers of the Nix C
 - **`nix-bindings-flake`** - Flake operations
 - **`nix-bindings-fetchers`** - Fetcher functionality (requires Nix ≥ 2.29)
 
-The `nix-bindings-util-sys` crate contains the generated FFI bindings and is not intended for direct use.
+The `*-sys` crates contain generated FFI bindings and are not intended for direct use.
 
 ## Features
 
@@ -211,6 +211,7 @@ For VSCode, load the dev shell via Nix Env Selector extension or direnv.
 
 ## Documentation
 
+- [Changelog](CHANGELOG.md)
 - [Nix C API Reference][C API]
 - [nix-cargo-integration][nix-cargo-integration]
 - [Hacking Guide](doc/hacking/test-ffi.md)

doc/maintainers/release.md

@@ -1,9 +1,18 @@
-
 # Release process
 
 This project uses simple tags, that trigger a release of all crates using Hercules CI.
 See [HCI Effects cargo publish workflow].
 
+## Before tagging
+
+- Update `CHANGELOG.md`:
+  - Make sure the Unreleased section is up to date
+  - Change it to the new version and release date
+
+## After tagging
+
+- Add a new Unreleased section to `CHANGELOG.md`
+
 Dissatisfied with the coarse grained release process? Complain to @roberth and he'll get it done for you.
 
 [HCI Effects cargo publish workflow]: https://docs.hercules-ci.com/hercules-ci-effects/reference/flake-parts/cargo-publish/#_releasing_a_version

nix-bindings-bdwgc-sys/Cargo.toml

@@ -4,6 +4,8 @@ version = "0.2.0"
 edition = "2021"
 build = "build.rs"
 license = "LGPL-2.1"
+repository = "https://github.com/nixops4/nix-bindings-rust"
+readme = "README.md"
 
 [lib]
 path = "src/lib.rs"

nix-bindings-bdwgc-sys/README.md

@@ -2,3 +2,7 @@
 
 This crate contains generated bindings for the Boehm-Demers-Weiser garbage collector (`bdw-gc`).
 **You should not have to use this crate directly,** and so you should probably not add it to your dependencies.
+
+## Changelog
+
+See the [nix-bindings-rust changelog](https://github.com/nixops4/nix-bindings-rust/blob/main/CHANGELOG.md).

nix-bindings-expr-sys/Cargo.toml

@@ -4,6 +4,8 @@ version = "0.2.0"
 edition = "2021"
 build = "build.rs"
 license = "LGPL-2.1"
+repository = "https://github.com/nixops4/nix-bindings-rust"
+readme = "README.md"
 
 [lib]
 path = "src/lib.rs"

nix-bindings-expr-sys/README.md

@@ -3,3 +3,7 @@
 This crate contains generated bindings for the Nix C API (`nix-expr-c`).
 **You should not have to use this crate directly,** and so you should probably not add it to your dependencies.
 Instead, use the `nix-bindings-expr` crate, which _should_ be sufficient.
+
+## Changelog
+
+See the [nix-bindings-rust changelog](https://github.com/nixops4/nix-bindings-rust/blob/main/CHANGELOG.md).

nix-bindings-expr/Cargo.toml

@@ -6,6 +6,7 @@ build = "build.rs"
 license = "LGPL-2.1"
 description = "Rust bindings to Nix expression evaluator"
 repository = "https://github.com/nixops4/nix-bindings-rust"
+readme = "README.md"
 
 [lib]
 path = "src/lib.rs"

nix-bindings-expr/README.md

@@ -0,0 +1,7 @@
+# nix-bindings-expr
+
+Rust bindings to the Nix expression evaluator.
+
+## Changelog
+
+See the [nix-bindings-rust changelog](https://github.com/nixops4/nix-bindings-rust/blob/main/CHANGELOG.md).

nix-bindings-fetchers-sys/Cargo.toml

@@ -4,6 +4,8 @@ version = "0.2.0"
 edition = "2021"
 build = "build.rs"
 license = "LGPL-2.1"
+repository = "https://github.com/nixops4/nix-bindings-rust"
+readme = "README.md"
 
 [lib]
 path = "src/lib.rs"

nix-bindings-fetchers-sys/README.md

@@ -3,3 +3,7 @@
 This crate contains generated bindings for the Nix C API (`nix-fetchers-c`).
 **You should not have to use this crate directly,** and so you should probably not add it to your dependencies.
 Instead, use the `nix-bindings-fetchers` crate, which _should_ be sufficient.
+
+## Changelog
+
+See the [nix-bindings-rust changelog](https://github.com/nixops4/nix-bindings-rust/blob/main/CHANGELOG.md).

nix-bindings-fetchers/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 license = "LGPL-2.1"
 description = "Rust bindings to Nix fetchers"
 repository = "https://github.com/nixops4/nix-bindings-rust"
+readme = "README.md"
 
 [lib]
 path = "src/lib.rs"

nix-bindings-fetchers/README.md

@@ -0,0 +1,7 @@
+# nix-bindings-fetchers
+
+Rust bindings to the nix-fetchers library.
+
+## Changelog
+
+See the [nix-bindings-rust changelog](https://github.com/nixops4/nix-bindings-rust/blob/main/CHANGELOG.md).

nix-bindings-flake-sys/Cargo.toml

@@ -4,6 +4,8 @@ version = "0.2.0"
 edition = "2021"
 build = "build.rs"
 license = "LGPL-2.1"
+repository = "https://github.com/nixops4/nix-bindings-rust"
+readme = "README.md"
 
 [lib]
 path = "src/lib.rs"

nix-bindings-flake-sys/README.md

@@ -3,3 +3,7 @@
 This crate contains generated bindings for the Nix C API (`nix-flake-c`).
 **You should not have to use this crate directly,** and so you should probably not add it to your dependencies.
 Instead, use the `nix-bindings-flake` crate, which _should_ be sufficient.
+
+## Changelog
+
+See the [nix-bindings-rust changelog](https://github.com/nixops4/nix-bindings-rust/blob/main/CHANGELOG.md).

nix-bindings-flake/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 license = "LGPL-2.1"
 description = "Rust bindings to Nix flakes"
 repository = "https://github.com/nixops4/nix-bindings-rust"
+readme = "README.md"
 
 [lib]
 path = "src/lib.rs"

nix-bindings-flake/README.md

@@ -0,0 +1,7 @@
+# nix-bindings-flake
+
+Rust bindings to Nix flakes.
+
+## Changelog
+
+See the [nix-bindings-rust changelog](https://github.com/nixops4/nix-bindings-rust/blob/main/CHANGELOG.md).

nix-bindings-store-sys/Cargo.toml

@@ -4,6 +4,8 @@ version = "0.2.0"
 edition = "2021"
 build = "build.rs"
 license = "LGPL-2.1"
+repository = "https://github.com/nixops4/nix-bindings-rust"
+readme = "README.md"
 
 [lib]
 path = "src/lib.rs"

nix-bindings-store-sys/README.md

@@ -3,3 +3,7 @@
 This crate contains generated bindings for the Nix C API (`nix-store-c`).
 **You should not have to use this crate directly,** and so you should probably not add it to your dependencies.
 Instead, use the `nix-bindings-store` crate, which _should_ be sufficient.
+
+## Changelog
+
+See the [nix-bindings-rust changelog](https://github.com/nixops4/nix-bindings-rust/blob/main/CHANGELOG.md).

nix-bindings-store/Cargo.toml

@@ -6,6 +6,7 @@ build = "build.rs"
 license = "LGPL-2.1"
 description = "Rust bindings to Nix store library"
 repository = "https://github.com/nixops4/nix-bindings-rust"
+readme = "README.md"
 
 [lib]
 path = "src/lib.rs"

nix-bindings-store/README.md

@@ -0,0 +1,7 @@
+# nix-bindings-store
+
+Rust bindings to the Nix store library.
+
+## Changelog
+
+See the [nix-bindings-rust changelog](https://github.com/nixops4/nix-bindings-rust/blob/main/CHANGELOG.md).

nix-bindings-util-sys/Cargo.toml

@@ -6,6 +6,7 @@ build = "build.rs"
 license = "LGPL-2.1"
 description = "Low-level FFI bindings to Nix utility library"
 repository = "https://github.com/nixops4/nix-bindings-rust"
+readme = "README.md"
 
 [lib]
 path = "src/lib.rs"

nix-bindings-util-sys/README.md

@@ -3,3 +3,7 @@
 This crate contains generated bindings for the Nix C API (`nix-util-c`).
 **You should not have to use this crate directly,** and so you should probably not add it to your dependencies.
 Instead, use the `nix-bindings-util` crate, which _should_ be sufficient.
+
+## Changelog
+
+See the [nix-bindings-rust changelog](https://github.com/nixops4/nix-bindings-rust/blob/main/CHANGELOG.md).

nix-bindings-util/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 license = "LGPL-2.1"
 description = "Rust bindings to Nix utility library"
 repository = "https://github.com/nixops4/nix-bindings-rust"
+readme = "README.md"
 
 [lib]
 path = "src/lib.rs"

nix-bindings-util/README.md

@@ -0,0 +1,7 @@
+# nix-bindings-util
+
+Rust bindings to the Nix utility library.
+
+## Changelog
+
+See the [nix-bindings-rust changelog](https://github.com/nixops4/nix-bindings-rust/blob/main/CHANGELOG.md).