The rust compiler supports building with some dependencies from For example, log and env_logger come from

In general, you should avoid adding dependencies to the compiler for several reasons:

  • The dependency may not be high quality or well-maintained, whereas we want the compiler to be high-quality.
  • The dependency may not be using a compatible license.
  • The dependency may have transitive dependencies that have one of the above problems.

TODO: what is the vetting process?

Permitted dependencies

The tidy tool has a list of crates that are allowed. To add a dependency that is not already in the compiler, you will need to add it to the list.