rust-lang/cargo · error

cannot specify both `@<VERSION>` and `--version <VERSION>`

Error message

cannot specify both `@<VERSION>` and `--version <VERSION>`

What it means

From resolve_crate (src/bin/cargo/commands/install.rs:328-342). Each crate spec may carry an inline version via `crate@version` (local_version) and the command also accepts a global --version flag. If both are present for the same crate, Cargo bails because the two sources of version requirements would conflict.

Source

Thrown at src/bin/cargo/commands/install.rs:335

                        "\n\n  tip: if you want to specify SemVer range, \
                             add an explicit qualifier, like '^{}'",
                        v
                    ));
                }
                bail!(msg);
            }
        }
    }
}

fn resolve_crate(
    krate: String,
    local_version: Option<VersionReq>,
    version: Option<&VersionReq>,
) -> crate::CargoResult<CrateVersion> {
    let version = match (local_version, version) {
        (Some(_), Some(_)) => {
            anyhow::bail!("cannot specify both `@<VERSION>` and `--version <VERSION>`");
        }
        (Some(l), None) => Some(l),
        (None, Some(g)) => Some(g.to_owned()),
        (None, None) => None,
    };
    Ok((krate, version))
}

View on GitHub (pinned to 0e07a15537)

Solutions

1. Pick one: use either `crate@version` OR `--version <ver>`, not both.
2. Prefer `--version` when installing multiple crates with the same requirement.
3. Prefer `crate@version` when each crate needs a distinct version.

Example fix

// before
cargo install ripgrep@1.2.3 --version 1.2.3

// after
cargo install ripgrep@1.2.3   # or: cargo install ripgrep --version 1.2.3

// Allow at most one source of version requirement per crate
fn version_sources_ok(has_at_version: bool, has_version_flag: bool) -> bool {
    !(has_at_version && has_version_flag)
}

fn has_single_version_source(spec: &str, version_flag_present: bool) -> bool {
    !(spec.contains('@') && version_flag_present)
}

When it happens

Trigger: `cargo install ripgrep@1.2.3 --version 1.2.3` or any combination where both the `@version` shorthand and `--version` are supplied.

Common situations: Mixing shorthand and explicit flag in a script; copy-pasting from two examples; automating install with redundant version specifiers.

Related errors

• missing crate name before '@'
• invalid character `+` in package name: `+{toolchain}` Us
• invalid package name: `{url}` Use `cargo install --git {
• crate name is empty
• argument for --color must be auto, always, or never, but fou

AI-assisted analysis of rust-lang/cargo@0e07a15537 (2026-08-06). Data as JSON: /data/errors/b084ebd21e190c9a.json. Report an issue: GitHub.