# 215 — Diagnosis

*2026-10-03.* `takeIn` registers a build's `Ref` as the branch the module follows. unifi was once
built with `ref=9c97a8a`, which became its followed ref. `sourceIs` matches a merge only to modules
whose ref is empty or the merged base — so every merge into main left unifi out — and `askTier`
re-asks `Source.Ref`, so every plan that rebuilt unifi built the same old commit again (its build
records all read "at 9c97a8a"). **Fix (branch `fix/issue-215-a-commit-is-never-a-branch-to-follow`,
commit 6784efa):** registration keeps the followed branch when a build names a commit; matching and
re-asking read a recorded commit as the default branch, healing existing records; a merge names the
modules of its repository it leaves out. Store-backed test fails without the fix.