# cargo-unmaintained
**Find unmaintained packages in Rust projects**
`cargo-unmaintained` is similar to [`cargo-audit`]. However, `cargo-unmaintained` finds unmaintained packages automatically using heuristics, rather than rely on users to manually submit them to the [RustSec Advisory Database].
`cargo-unmaintained` defines an unmaintained package X as one that satisfies one of 1 through 3 below:
1. X's repository is archived (see [Notes] below).
2. X is not a member of its named repository.
3. Both a and b below.
a. X depends on a package Y whose latest version:
- is incompatible with the version that X depends on
- was released over a year ago (a configurable value)
b. Either X has no associated repository, or its repository's last commit was over a year ago (a configurable value).
As of 2024-12-23, the RustSec Advisory Database contains 132 active advisories for unmaintained packages. Using the above conditions, `cargo-unmaintained` automatically identifies 97 (73%) of them. These results can be reproduced by running the [`rustsec_advisories`] example within this repository.
### Notes
- To check whether packages' repositories have been archived, set the `GITHUB_TOKEN_PATH` environment variable to the path of a file containing a [personal access token]. If unset, this check will be skipped.
- The above conditions consider a "leaf" package (i.e., a package with no dependencies) unmaintained only if conditions 1 or 2 apply.
- The purpose of the "over a year ago" qualifications in condition 3 is to give package maintainers a chance to update their packages. That is, an incompatible upgrade to one of X's dependencies could require time-consuming changes to X. Without this check, `cargo-unmaintained` would produce many false positives.
- Of the 35 packages in the RustSec Advisory Database _not_ identified by `cargo-unmaintained`:
- 11 do not build
- 3 are existent, unarchived leaves
- 2 were updated within the past 365 days
- 19 were not identified for other reasons
## Output
`cargo-unmaintained`'s output includes the number of days since a package's repository was last updated, along with the dependencies that cause the package to be considered unmaintained.
For example, the following is the output produced by running `cargo-unmaintained` on [Cargo 0.74.0] on 2023-11-11:
<img src="etc/output.png" width=725>
## Installation
```sh
cargo install cargo-unmaintained
```
## Usage
```
Usage: cargo unmaintained [OPTIONS]
Options:
--color <WHEN> When to use color: always, auto, or never [default: auto]
--fail-fast Exit as soon as an unmaintained package is found
--json Output JSON (experimental)
--max-age <DAYS> Age in days that a repository's last commit must not exceed for the
repository to be considered current; 0 effectively disables this check,
though ages are still reported [default: 365]
--no-cache Do not cache data on disk for future runs
--no-exit-code Do not set exit status when unmaintained packages are found
--no-warnings Do not show warnings
-p, --package <NAME> Check only whether package NAME is unmaintained
--save-token Read a personal access token from standard input and save it to
$HOME/.config/cargo-unmaintained/token.txt
--tree Show paths to unmaintained packages
--verbose Show information about what cargo-unmaintained is doing
-h, --help Print help
-V, --version Print version
The `GITHUB_TOKEN_PATH` environment variable can be set to the path of a file containing a personal
access token. If set, cargo-unmaintained will use this token to authenticate to GitHub and check
whether packages' repositories have been archived.
Alternatively, the `GITHUB_TOKEN` environment variable can be set to a personal access token.
However, use of `GITHUB_TOKEN_PATH` is recommended as it is less likely to leak the token.
If neither `GITHUB_TOKEN_PATH` nor `GITHUB_TOKEN` is set, but a file exists at
$HOME/.config/cargo-unmaintained/token.txt, cargo-unmaintained will use that file's contents as a
personal access token.
Unless --no-exit-code is passed, the exit status is 0 if no unmaintained packages were found and no
irrecoverable errors occurred, 1 if unmaintained packages were found, and 2 if an irrecoverable
error occurred.
```
## Ignoring packages
If a workspace's `Cargo.toml` file includes a `workspace.metadata.unmaintained.ignore` array, all packages named therein will be ignored. Example:
```toml
[workspace.metadata.unmaintained]
ignore = ["matchers"]
```
## Testing
Some tests are "externally influenced," i.e., they rely on data from external sources. To run these tests, enable the `ei` feature, e.g., use the following command:
```sh
cargo test --features=ei
```
## Known problems
- If a package is renamed from X to Y, it is immediately considered unmaintained because the package's repository no longer contains a package named X. ([#441])
- If a project relies on an old version of a package, `cargo-unmaintained` may fail to flag the package as unmaintained (i.e., may produce a false negative). The following is a sketch of how this can occur.
- The project relies on version 1 of package X, which has no dependencies.
- Version 2 of package X exists, and adds version 1 of package Y as a dependency.
- Version 2 of package Y exists.
Note that version 1 of package X appears maintained, but version 2 does not. Ignoring a few details, version 2 satisfies condition 3 above.
`cargo-unmaintained` does not, in all cases, check whether the latest version of a package is used, as doing so would be cost prohibitive. A downside of this choice is that false negatives can result.
Note that false _positives_ should not arise in a corresponding way. Before flagging a package as unmaintained, `cargo-unmaintained` verifies that the package's latest version would be considered unmaintained as well.
## Anti-goals
`cargo-unmaintained` is not meant to be a replacement for [`cargo-upgrade`]. `cargo-unmaintained` should not warn just because a package needs to be upgraded.
## Semantic versioning policy
We reserve the right to change the following and to consider such changes non-breaking:
- what data is stored in the cache, as well as how that data is stored
- the output produced the experimental `--json` option
## License
`cargo-unmaintained` is licensed and distributed under the AGPLv3 license. [Contact us](mailto:opensource@trailofbits.com) if you're looking for an exception to the terms.
[#441]: https://github.com/trailofbits/cargo-unmaintained/issues/441
[Cargo 0.74.0]: https://github.com/rust-lang/cargo/tree/d252bce6553c8cc521840c9dd6b9f6cd4aedd8b0
[Notes]: #notes
[RustSec Advisory Database]: https://github.com/RustSec/advisory-db/
[`cargo-audit`]: https://github.com/RustSec/rustsec/tree/main/cargo-audit
[`cargo-upgrade`]: https://github.com/killercup/cargo-edit?tab=readme-ov-file#cargo-upgrade
[`rustsec_advisories`]: ./examples/rustsec_advisories.rs
[personal access token]: https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/managing-your-personal-access-tokens