After `banger update` swaps binaries, install.toml needs to reflect
the just-installed identity. The previous code passed
buildinfo.Current().{Commit,BuiltAt} into installmeta.UpdateBuildInfo
— but buildinfo.Current() in the running CLI is the OLD pre-swap
binary's identity (we're it), not the staged one. install.toml's
version field got refreshed to target.Version while commit and
built_at stayed pinned at the previous release. `banger doctor`
compares the running CLI's three fields against install.toml's
three fields and so raised a false-positive drift warning on
every update.
Fix: after the swap, exec /usr/local/bin/banger version, parse the
three-line output, and write all three fields to install.toml. If
the exec fails for any reason we fall back to the old behaviour
(version + stale commit/built_at) with a warning, since install.toml
drift is a doctor warning not a broken host — same posture as
before for the failure path.
The parser is split out (parseVersionOutput) and table-tested:
happy path, whitespace-tolerance, missing-field rejection, empty
input rejection, ignoring unrelated lines.
Caught by running v0.1.0 → v0.1.1 live as the first end-to-end
smoke test of the self-update flow, which was the whole point of
that exercise.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
