Function hash_with_report 

pub fn hash_with_report(
    root: &Path,
    inputs: &ClosureInputs,
) -> Result<Closure, ClosureError>

2026-09-26: Hash a target’s closure and report the quoted includes that named no file on disk.

An unresolvable include is recorded, not fatal. Its name still reaches the digest twice: through the including file’s bytes, and through the unresolved set, hashed under its own label. What stays uncovered is the content of a header the compiler finds some other way. The kernels build prints each unresolved entry as a cargo:warning.

Errors

ClosureError::Io when a source, an included file or a config cannot be read.