1. Manually testing:
Run `nix develop` from the root of the repo.
Go to tunnelbroker service directory `services/tunnelbroker` and run the Cargo building process `cargo build` or `cargo run`.
The Rust application will be successfully built.
2. CI Testing:
These diff changes are included as a part of the stack in the later D5461 diff, where the changes to CI build commands are made. The CI succeded on the D5461 which reflects that these changes are passing the build.