Exclude sbt-git's own keys from sbt's lintUnused check

[jakubjanecek]

Fixes #379.

Problem

GitPlugin sets a number of keys eagerly in buildSettings/projectSettings that a build only consumes when git versioning is enabled, or that are read by commands rather than by other settings. sbt's lintUnused check cannot see that, so it reports them as unused and points at GitPlugin.scala:

[warn] * ThisBuild / gitUncommittedChanges
[warn] * ThisBuild / scmInfo
[warn] * root / gitDescribedVersion

Worth noting why this only shows up for some builds: LintUnused only reports a candidate whose recorded position passes isLocallyDefined, i.e. some position's path contains a /. The released sbt-git 2.1.0 sbt-2 artifact recorded positions whose "path" is the setting's source text (ThisBuild / gitUncommittedChanges := …), which contains a / and therefore passes; a rebuild of the same source with sbt 2.0.0 today records LinePosition(GitPlugin.scala, 135) and the keys silently pass instead. So the warnings can appear and disappear across releases, and the fix should not depend on that.

Fix

Add globalSettings that appends the keys this plugin owns to Global / excludeLintKeys. The exclusion matches on key label, so it is independent of the scope a key ends up in and of the positions baked into the published plugin.

excludeLintKeys is preferred over withRank(KeyRanks.Invisible), which would also hide these user-facing keys from settings/inspect.

The list also covers gitRemoteRepo and gitBranch, which nothing in the plugin ever reads, so users who set them were being warned at too. scmInfo is included because the plugin is what sets it in buildSettings — that is the second warning in the issue.

Test

New scripted test src/sbt-test/lint/exclude-lint-keys sets git keys that nothing in the build consumes and asserts LintUnused.lintUnused reports none of the plugin's keys. Without the plugin change it fails with lintUnused reported sbt-git keys: gitRemoteRepo.

Verification

• Reproduced the issue on sbt 2.0.0 with sbt-ci-release 1.12.1 and released sbt-git 2.1.0: the exact warnings for ThisBuild / gitUncommittedChanges and root / gitDescribedVersion; adding those labels to excludeLintKeys turns the run into [success] ok.
• Locally published before/after builds in a scratch project: unfixed reports [baseVersion, useGitDescribe, gitRemoteRepo], fixed reports [] — on sbt 2.0.0 and on sbt 1.x, confirming plugin globalSettings are applied after sbt's own excludeLintKeys := … in both.
• +compile, ++3.x test, scalafmtCheckAll / scalafmtSbtCheck, and ++3.x scripted lint/exclude-lint-keys pass locally. The sbt 1.x scripted suite could not be run locally (sbt 1.5.8 ships Scala 2.12.14, which fails with bad constant pool index on JDK 21/26 — pre-existing, existing tests fail identically), so CI covers that side.

🤖 Generated with Claude Code

[jakubjanecek]

Closing because it was found out the issue cannot be reproduced in the latest snapshot.