从带有 main.rs 文件的本地 crate 导入时未解决的导入

Question

I have included a library as a submodule in my program. The structure looks like this:

.
├── my_lib/
     ├── Cargo.toml
     └── src/
          ├── lib/
               ├── mod.rs
               └── foo.rs
          └── main.rs
├── src/
     └── main.rs
└── Cargo.toml

In my program's Cargo.toml file I have added the dependency following this answer :

[dependencies]
my_lib = { path = "./my_lib" }

However I'm not able to use this library inside my program, I'm a bit new to Rust and this import system is very confusing to me. I've tried this in main.rs :

use my_lib::foo;

But I get an unresolved import 'my_lib' error.

Answer 1

A crate can be either a library or an executable, not both. Your my_lib contains a main.rs file, which means Cargo will treat it as an executable file. You cannot import from an executable.

You will need to restructure your code. Perhaps you actually meant for my_lib to be a library, in which case it should have a top-level lib.rs . You probably want to:

• delete my_lib/src/main.rs
• move my_lib/src/lib/mod.rs to my_lib/src/lib.rs
• move my_lib/src/lib/foo.rs to my_lib/src/foo.rs

See also:

• Rust package with both a library and a binary?