Enum CanonicalHome 

pub enum CanonicalHome {
    Monorepo(PathBuf),
    StandaloneExport,
}

Where the twin-drift guard should look for the canonical mirror.yml.

The canonical copy lives at <monorepo root>/.yah/infra/cloud-init/mirror.yml and is what load_template — and therefore every real provision — actually reads. The embedded DEFAULT_TEMPLATE is only the fallback for when that file is absent, so the two must not be allowed to diverge.

Resolving that root is not as simple as “first ancestor with a .yah/”. oss/yubaba is a deliberately independent cargo workspace (monorepo CLAUDE.md, “Co-developed OSS repos”), and its own .yah/ carries nothing but a .gitignore — so an ancestor walk keyed on .yah/ stops AT oss/yubaba, where the canonical file can never exist. That is exactly how embedded_template_matches_workspace_canonical spent months taking its “file not there yet, nothing to compare” branch and asserting nothing while the twin drifted 128 lines behind (R870-B25).

The discriminator is .yah/infra/: the monorepo has it (machines, cloud-init, preseed, rules, …), and a standalone export of this subtree — where the repo root genuinely is oss/yubaba — does not.

Variants

Monorepo(PathBuf)

Built inside the yah monorepo. The canonical mirror.yml MUST exist under this root; its absence is a defect, never a bootstrap case.

StandaloneExport

Built from the standalone yubaba export, which ships no .yah/infra/ and therefore no canonical copy. Nothing on disk to compare against — the embedded template is the only template there is.

Trait Implementations

impl Debug for CanonicalHome

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for CanonicalHome

impl PartialEq for CanonicalHome

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for CanonicalHome