Binary targets are automatically built if there is an integration test or
benchmark being selected to {{lower actionverb}}. This allows an integration
test to execute the binary to exercise and test its behavior.
The `CARGO_BIN_EXE_<name>`
[environment variable](../reference/environment-variables.html#environment-variables-cargo-sets-for-crates)
is set when the integration test is built so that it can use the
[`env` macro](https://doc.rust-lang.org/std/macro.env.html) to locate the
executable.