⚠️ libyml is deprecated — migrate to a maintained alternative

libyml is unmaintained. v0.0.6 is a thin compatibility shim
that forwards every call to the upstream
unsafe-libyaml (which
libyml was originally forked from), so existing call sites keep
working while you plan a migration.

Security — RUSTSEC-2025-0067 fixed in 0.0.6

RUSTSEC-2025-0067
flagged all libyml ≤ 0.0.5 as unsound — the
libyml::string::yaml_string_extend function had a code path
that could trigger undefined behaviour. v0.0.6 removes the
vulnerable surface entirely — the entire libyml::string
module is gone from the source tree alongside the rest of the
hand-translated C-libyaml copy, and every public function is now
re-exported from unsafe-libyaml.

cargo audit will still warn anyway because the RustSec
advisory database tracks the crate's unmaintained status rather
than code presence. See the README's "cargo audit" section
for a copy-paste .cargo/audit.toml snippet.

Maintained alternatives

Full mapping tables and behavioural notes:
MIGRATION.md.

What changed in 0.0.6

• ~18 000 lines of hand-translated C-libyaml code deleted from
  src/; every public function is now re-exported from
  unsafe-libyaml.
• Historical path-form sub-modules (libyml::api,
  libyml::decode, libyml::document, libyml::dumper,
  libyml::loader, libyml::yaml, libyml::success) retained
  as thin re-exports.
• libyml::memory and libyml::string retained as empty stub
  modules with deprecation notes (their former contents — the
  C-allocator wrappers and the yaml_string_extend unsound
  helper — are gone).
• Cargo.toml: single runtime dep on unsafe-libyaml = "0.2.11".
  Dual-licensed MIT / Apache-2.0 (was MIT-only) to match upstream.
• v0.0.5 test and example files retained where they survive the
  shim's compatibility boundary, so the migration shape is
  visible side-by-side with the working tree.

Breaking changes (documented in MIGRATION.md)

Most downstream code compiles unchanged against this shim. Three
deltas flow through from the upstream:

1. c_int → bool for boolean parameters
   (yaml_scalar_event_initialize(..., 1, 1, …) →
   yaml_scalar_event_initialize(..., true, true, …)).
2. libyml::success::Success is no longer a nameable type —
   read .ok on return values directly.
3. PascalCase enum variants stay valid in value position but
   rename to YAML_* SCREAMING_SNAKE_CASE in match arms.

Diff at a glance

76 files changed, 2 449 insertions, 20 584 deletions.

Release v0.0.5 - 2024-08-24

LibYML (a fork of unsafe-libyaml)

LibYML is a Rust library for working with YAML data, forked from unsafe-libyaml. It offers a safe and efficient interface for parsing, emitting, and manipulating YAML data.

Features

• Serialization and Deserialization: Easy-to-use APIs for serializing Rust structs and enums to YAML and vice versa.
• Custom Struct and Enum Support: Seamless serialization and deserialization of custom data types.
• Comprehensive Error Handling: Detailed error messages and recovery mechanisms.
• Streaming Support: Efficient processing of large YAML documents.
• Alias and Anchor Support: Handling of complex YAML structures with references.
• Tag Handling: Support for custom tags and type-specific serialization.
• Configurable Emitter: Customizable YAML output generation.
• Extensive Documentation: Detailed docs and examples for easy onboarding.
• Safety and Efficiency: Minimized unsafe code with an interface designed to prevent common pitfalls.

Changelog 📚

Merge pull request #4 from sebastienrousseau/feat/libyml

What's Changed

• feat(libyml): ✨ v0.0.5 by @sebastienrousseau in #4

Full Changelog: v0.0.4...v0.0.5

Release v0.0.4 - 2024-07-20

LibYML (a fork of unsafe-libyaml)

This library is a fork of unsafe-libyaml, a version of libyaml translated from C to unsafe Rust with the assistance of c2rust.

This project, has been renamed to LibYML for simplicity and to avoid confusion with the original unsafe-libyaml crate which is now archived and no longer maintained.

New Features

• Code Decoupling: Major refactoring to improve modularity:

  • Created document.rs and decode.rs to decouple functionality from api.rs
  • Introduced memory.rs for memory management functions
  • Added internal.rs for internal helper functions

• Enhanced Memory Management: Implemented dedicated functions for memory allocation, reallocation, and freeing in memory.rs

• Default Trait Implementation: Added Default trait implementation for YAML types

Improvements

• Error Handling: Implemented consistent error handling throughout the codebase

• Code Formatting: Resolved various formatting issues and addressed Clippy warnings

• Documentation: Minor tweaks and versioning updates in the documentation

Bug Fixes

• Fixed a critical segmentation fault issue
• Resolved several compiler warnings and errors:
  • Removed unnecessary qualifications
  • Fixed unneeded return statements
  • Corrected misuse of assert_eq! with boolean literals

Testing

• Expanded Test Suite:
  • Added numerous new unit tests across different modules
  • Enhanced and reorganized the YAML parser test suite
  • Implemented specific tests for yaml.rs and yaml_malloc

Other Changes

• Updated CodeCov token for improved coverage reporting
• Minor changes to library management

Installation

[dependencies]
libyml = "0.0.4"

Release notes are available under GitHub releases.

Rust Version Compatibility

This library is compatible with Rust 1.60 and above.

License

MIT license, same as libyaml.

Changelog 📚

• 0.0.4 by @sebastienrousseau in #3

Full Changelog: 0.0.3...v0.0.4

LibYML (a fork of unsafe-libyaml)

This library is a fork of unsafe-libyaml, a version of libyaml translated from C to unsafe Rust with the assistance of c2rust.

This project, has been renamed to LibYML for simplicity and to avoid confusion with the original unsafe-libyaml crate which is now archived and no longer maintained.

Credits and Acknowledgements

This library is a fork of the excellent work done by David Tolnay and the maintainers of the unsafe-libyaml library.

LibYML has now evolved into a separate library with its own goals and direction in mind and does not intend to replace the original unsafe-libyaml crate.

If you are currently using unsafe-libyaml in your projects, we recommend carefully evaluating your requirements and considering the stability and maturity of the original library as well as looking at the features and improvements offered by other libraries in the Rust ecosystem.

I would like to express my sincere gratitude to David Tolnay and the unsafe-libyaml and libyaml maintainers for their valuable contributions to the Rust and C programming communities.

[dependencies]
libyml = "0.0.3"

Release notes are available under GitHub releases.

Rust Version Compatibility

This library is compatible with Rust 1.60 and above.

License

MIT license, same as libyaml.

Changelog 📚

Enhancements

Forked unsafe-libyaml

• Hard reset: Hard reset to the latest @dtolnay latest release to keep traceability and retain commits history to the original unsafe-libyaml codebase and credits to the maintainers.
• Renaming: This project, has been renamed to LibYML for simplicity and to avoid confusion with the original unsafe-libyaml crate which is now archived and no longer maintained.

Changes:

• Build:

  • Minor updates on linting conditions to improve code quality.

• Chore:

  • Upgraded library version to 0.0.3 for enhanced functionality.

• Fixes:

  • Removed incorrect copyrights that were present.
  • Fixed formatting issues in the codebase.
  • Updated documentation in lib.rs for clarity.
  • Resolved a breaking test issue.
  • Addressed missing_docs warnings.
  • Resolved a warning related to type implementation.
  • Refactored CI workflows for better efficiency.
  • Ensured consistent code formatting.

What's Changed

• 0.0.2 by @sebastienrousseau in #1
• 0.0.3 by @sebastienrousseau in #2

New Contributors

• @sebastienrousseau made their first contribution in #1

Full Changelog: https://github.com/sebastienrousseau/libyml/commits/0.0.3