Function calculate

fn calculate(
    build_runner: &mut BuildRunner<'_, '_>,
    unit: &Unit,
) -> CargoResult<Arc<Fingerprint>>

Calculates the fingerprint for a Unit.

This fingerprint is used by Cargo to learn about when information such as:

• A non-path package changes (changes version, changes revision, etc).
• Any dependency changes
• The compiler changes
• The set of features a package is built with changes
• The profile a target is compiled with changes (e.g., opt-level changes)
• Any other compiler flags change that will affect the result

Information like file modification time is only calculated for path dependencies.