I have a Rust library that implements a lint plugin. I want to include compiletest, but not require it outside of testing. What is the correct way to specify that the dependency is for testing only?
Use dev-dependencies. From the Cargo docs:
You can add a
[dev-dependencies]section to yourCargo.tomlwhose format is equivalent to[dependencies]:[dev-dependencies] tempdir = "0.3"Dev-dependencies are not used when compiling a package for building, but are used for compiling tests, examples, and benchmarks.
When possible, you should also use Cargo's resolver version 2 to better handle complicated dev-dependency cases.