# Resolvo: Fast package resolver written in Rust ![License][license-badge] [![crates.io][crates-badge]][crates] [![Build Status][build-badge]][build] [![Project Chat][chat-badge]][chat-url] [![Docs][docs-main-badge]][docs-main] [license-badge]: https://img.shields.io/badge/license-BSD--3--Clause-blue?style=flat-square [build-badge]: https://img.shields.io/github/actions/workflow/status/mamba-org/resolvo/rust-compile.yml?style=flat-square&branch=main [build]: https://github.com/mamba-org/resolvo/actions [chat-badge]: https://img.shields.io/discord/1082332781146800168.svg?label=&logo=discord&logoColor=ffffff&color=7389D8&labelColor=6A7EC2&style=flat-square [chat-url]: https://discord.gg/kKV8ZxyzY4 [docs-main-badge]: https://img.shields.io/badge/docs-main-yellow.svg?style=flat-square [docs-main]: https://docs.rs/resolvo [crates]: https://crates.io/crates/resolvo [crates-badge]: https://img.shields.io/crates/v/resolvo.svg Resolvo implements a fast package resolution algorithm based on CDCL SAT solving. ### Projects using `resolvo` - [`rip`](https://github.com/prefix-dev/rip): An async package resolver and installer for Python PyPI packages - [`rattler`](https://github.com/mamba-org/rattler): Conda package resolver and installer (non-async) - [`resolvo-rpm`](https://github.com/prefix-dev/resolvo-rpm): Experimental RPM resolver for Fedora / RedHat / OpenSUSE ... RPM packages - ... add yours! ## Features If resolvo is unable to find a solution it outputs a human-readable error message: ``` The following packages are incompatible ├─ bluesky-widgets >=0, <100 can be installed with any of the following options: │ └─ bluesky-widgets 42 would require │ └─ suitcase-utils >=0, <54, which can be installed with any of the following options: │ └─ suitcase-utils 53 └─ suitcase-utils >=54, <100 cannot be installed because there are no viable options: └─ suitcase-utils 54, which conflicts with the versions reported above. ``` Resolve provides a generic interface which allows integrating the solver with a variety of package managers. For instance resolvo is used in [rattler](https://github.com/mamba-org/rattler) and [pixi](https://github.com/prefix-dev/pixi) to solve packages from the conda ecosystem. Originally resolvo started out as a port/fork of [libsolv](https://github.com/openSUSE/libsolv) but it has since then diverged substantially. However, the same CDCL algorithm based on MiniSats [An Extensible SAT-solver](http://minisat.se/downloads/MiniSat.pdf) is still used underneath. Major differences compared to libsolv are: * Resolvo does not come with built-in support for several packaging ecosystems but instead provides a generic interface to allow it to be used in different scenarios. * Resolvo has support for incremental/lazy solving. This allows users to quickly find solutions in ecosystems where retrieving package metadata is expensive. * Resolvo is considerably faster than libsolv in large complex cases. * Resolvo can easily be used in multithreaded environments. * Resolvo provides human-readable error messages out-of-the-box. * Resolvo optionally provides an async interface to allow concurrent metadata fetching. * However, Libsolv is more extensive and supports more complex queries. ## Contributing 😍 We would love to have you contribute! See the CONTRIBUTION.md for more info. For questions, requests or a casual chat, we are very active on our discord server. You can [join our discord server via this link][chat-url].