Rust error E0464: the compiler found multiple library files with the requested crate name

The compiler team's explanation

The compiler found multiple library files with the requested crate name.

// aux-build:crateresolve-1.rs
// aux-build:crateresolve-2.rs
// aux-build:crateresolve-3.rs

extern crate crateresolve;
//~^ ERROR multiple candidates for `rlib` dependency `crateresolve` found

fn main() {}

This error can occur in several different cases -- for example, when using extern crate or passing --extern options without crate paths. It can also be caused by caching issues with the build directory, in which case cargo clean may help.

In the above example, there are three different library files, all of which define the same crate name. Without providing a full path, there is no way for the compiler to know which crate it should use.

From rustc --explain E0464 (1.99.0), part of the Rust project, MIT or Apache-2.0. Official page.