Clippy lint · Cargo · checked with Clippy 0.1.99

clippy::multiple_crate_versions: Checks to see if multiple versions of a crate are being used

What it meansChecks to see if multiple versions of a crate are being used. It is in the cargo group and off by default.

Does it matter?

This bloats the size of targets, and can lead to confusing error messages when structs or traits are used interchangeably between different versions of a crate.

Checks on Cargo.toml metadata. Off by default.

How to fix it

Clippy does not fix this one automatically. Change the code by hand:

Turn it off, or on

It is off by default. To use it, set it to warn or deny:

Whole crate (Cargo.toml)

[lints.clippy]
multiple_crate_versions = "warn"

In code

#![warn(clippy::multiple_crate_versions)]

One run

cargo clippy -- -W clippy::multiple-crate-versions

The [lints] table needs Rust 1.74 or newer. In a workspace, put it under [workspace.lints.clippy] and add [lints] workspace = true to each member.

Settings in clippy.toml

allowed-duplicate-crates: A list of crate names to allow duplicates of

Cargogroup

allowdefault level

nofixed by cargo clippy --fix

pre 1.29.0added in Rust

Clippy's own documentation

What it does

Checks to see if multiple versions of a crate are being used.

Why is this bad?

This bloats the size of targets, and can lead to confusing error messages when structs or traits are used interchangeably between different versions of a crate.

Known problems

Because this can be caused purely by the dependencies themselves, it’s not always possible to fix this issue. In those cases, you can allow that specific crate using the allowed-duplicate-crates configuration option.

Example

[dependencies]
ctrlc = "=3.1.0"
ansi_term = "=0.11.0"

Configuration

allowed-duplicate-crates: A list of crate names to allow duplicates of

(default: [])

From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.

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