werkator/docs/plan/18-remove-branches-section.md

Step 18: Remove the legacy branches section

Prerequisites: none in code — v0.9.19 already made builds and branches either-or. Read README.md first. Scheduled for roughly 2026-09-05, one week after v0.9.19 (2026-08-29), and only once the precondition below holds.

Build definitions describe a build completely since v0.9.19, and branches is read only while a configuration defines no build at all. This step deletes the section, its deprecated autoBuild schedule, and the either-or branch in the loader, and turns a leftover branches: key into a named error instead of a silent loss of settings.

Precondition Check (run first, do not skip)

The removal adds a rejection by name: a configuration file that still carries a branches: key is refused, because a silently ignored section is exactly the failure this step exists to prevent — and the gitTally.version check cannot catch it, since it only bites files that declare a version, which none of the hs.hsadmin.ng configs do.

So no configuration still in play may contain the section. On vm4006:

ssh tallyman@vm4006.hostsharing.net 'cd ~/hs.hsadmin.ng && grep -n "^branches:" .git/gittally/.gittally.yml; for b in $(git for-each-ref --format="%(refname:short)" refs/remotes/origin | sed "s|origin/||"); do if git cat-file -e origin/$b:.gittally.yml 2>/dev/null && git show origin/$b:.gittally.yml | grep -qE "^branches:"; then echo "still legacy: $b"; fi; done'

Expected output: nothing at all.

As of 2026-08-29 this listed master and five mihoe/… branches, plus the machine config. The plan was: merge mihoe/reactivate-pi-test (the first branch with the new shape) to master, rebase the other branches onto the new master, then run this step. Branches without a committed .gittally.yml are fine — they build from the machine config.

Note that branches: also exists as the selector key inside a build definition (builds.<name>.branches: ["master"]). That one stays. Only the top-level section goes. The grep above anchors at the line start for exactly that reason.

Code

• config/GitTallyConfig.kt: drop the branches property and AutoBuildConfig, and BranchConfig.autoBuild with it. Rename BranchConfig to BuildSettings — with the section gone it is no longer a schema type but the resolved answer to "what does this build run", which is all it is used for. buildSettings(branch, build) then no longer needs the branch lookup: effectiveBuildDefinitions()[build]?.applyTo(BuildSettings()) ?: BuildSettings(). Keep the branch parameter — the callers pass it and a later per-branch concern would need it back.
• config/ConfigLoader.kt: delete mergeBranchDefaults, the legacy arm of resolveBuildSections (it becomes just mergeBuildDefaults), the "branches" entry in the section loop of stripPinned, and LEGACY_BRANCHES_WARNING. Add the rejection: a branches key in a file throws, scoped like the version check — the machine and project config abort the start (checkVersion's call sites in loadRaw), a branch's committed config fails only that branch's builds (withBranchLayer). Reuse ConfigVersionException or add a sibling; the message must name the file and say where the settings belong now.
• watcher/Watcher.kt: delete enqueueDeprecatedAutoBuilds, its call in enqueueDueBranches, and the warnedDeprecatedAutoBuild flag.
• config/ConfigVersion.kt: set FORMAT_BROKE_IN to this release's version and FORMAT_BROKE_DESCRIPTION to something like "the per-branch branches section was replaced by build definitions". This is the first real use of that mechanism: a file declaring gitTally.version.since below this release is then refused with a message naming the change.
• commands/InitCommand.kt: nothing — the generated template has been builds-only since v0.9.19. Verify with gittally init in a scratch repo.

Tests

branches:-shaped YAML in tests must move to builds: (as of 2026-08-29):

• config/ConfigLoaderTest.kt — most occurrences; also delete the test "branches is honored while no build is defined and ignored as soon as one is" and replace it with one asserting the rejection.
• build/BuildExecutorTest.kt (the harness config and one inline config), artifacts/BuildExecutorArtifactIntegrationTest.kt, artifacts/FileArtifactStoreTest.kt, build/DockerBuildRunnerTest.kt, build/DispatchingBuildRunnerTest.kt, server/UiControllerTest.kt.
• watcher/WatcherTest.kt — the autoBuildConfig helper and the deprecated-schedule tests go; the atTimes tests stay.

Do not blind-replace: branches: [...] inside a build definition is the selector and must be left alone.

Add a test that a build whose definition was removed from the config still resolves to usable defaults — that path used to fall back to the branch settings.

Documentation

• docs/configuration.md: delete the section "The legacy branches section"; drop the "only while nothing defines a build" qualifier from the branch-layer section.
• AGENTS.md: the invariant bullet starting "builds or the legacy branches, never both" becomes the rejection rule.
• .claude/skills/architecture/SKILL.md: resolveBuildSections no longer chooses between two sections.
• docs/migration-from-legacy.md: already maps to builds.<name>; re-check it reads correctly without the legacy section existing.

Production

The machine config on vm4006 was rewritten for v0.9.19 and still carries its legacy block as the rollback path to v0.9.18 (backup: .git/gittally/.gittally.yml.20260829T085959Z.bak). Delete the block — everything below the comment marking it as legacy — before deploying this release, with a fresh timestamped backup. The file keeps git, server, builds.default, and builds.master. It is 600 by design; a shell redirect creates 644, so check the mode afterwards.

Deploy as usual (docs/plan/15-runtime-bundle-distribution.md), only while /api/builds/current is [].

Verification

• gittally config:print --full on vm4006 before the restart: no branches in the output, builds.default and builds.master complete, master still inheriting docker.enabled: true and network: host.
• After the restart: no warnings about a branches section, the watcher polls without errors, and a branch build starts in hsadmin-ng-build-env:latest.
• Deliberately: point the running instance at a scratch repository whose config still has branches: and confirm the error names the file.

Rollback

Keep ~/opt/gittally.<previous>.bak and the config backup. A rollback needs both, because the previous version reads the machine config's branches block for its sandbox policy and this step deletes it.