X_WORKSPACE_DEP_UNDECLARED
Means
a workspace imports another workspace its own package.json does not declare
Typical cause
an import added long after the scaffold, or a generator that emitted the import and not the edge. The graph then exists only inside tsc — affected-package detection, bun --filter ordering and blast radius all read manifests, and a missing edge makes each of them silently answer too small a set. Shipped source only: a test file's import is not judged, because packages/* here declares no devDependencies by design and the root's hoist is what resolves them
Fix
add the dependency the finding names — it carries the manifest path and the exact line, e.g. "@demo/web": "0.0.0"