| # crates.io dependencies |
| |
| The Rust compiler supports building with some dependencies from `crates.io`. |
| Examples are `log` and `env_logger`. |
| |
| In general, |
| you should avoid adding dependencies to the compiler for several reasons: |
| |
| - The dependency may not be of high quality or well-maintained. |
| - The dependency may not be using a compatible license. |
| - The dependency may have transitive dependencies that have one of the above |
| problems. |
| |
| <!-- date-check: Aug 2025 --> |
| Note that there is no official policy for vetting new dependencies to the compiler. |
| Decisions are made on a case-by-case basis, during code review. |
| |
| ## Permitted dependencies |
| |
| The `tidy` tool has [a list of crates that are allowed]. To add a |
| dependency that is not already in the compiler, you will need to add it to the list. |
| |
| [a list of crates that are allowed]: https://github.com/rust-lang/rust/blob/9d1b2106e23b1abd32fce1f17267604a5102f57a/src/tools/tidy/src/deps.rs#L73 |
