Show the command a build actually runs on its artifact page

The artifact page read `branches.<branch>.buildCommand` from the primary
config only, so for a named build on a branch with its own config it showed
a command that build never ran — on vm4006 it showed the host config's
command for a build that ran the branch definition's `pitestFull`.

Resolving "what does this build run" now has one implementation,
`GitTallyConfig.buildSettings(branch, build)`: the branch entry with the
build definition's overrides applied last. The executor uses it, and the
page resolves it against the branch layer committed at the build's own
commit — the same inputs the executor had.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/main/kotlin/de/hoennig/gittally/build/BuildExecutor.kt

@@ -474,12 +474,10 @@ class BuildExecutor(
         runningBuild: RunningBuild,
         workingDir: Path,
         worktree: Path,
-    ): BranchConfig {
-        val config = configLoader.loadForWorktree(workingDir, worktree)
-        val branchConfig = config.branches[runningBuild.branch] ?: config.branches["default"] ?: BranchConfig()
-        val definition = config.effectiveBuildDefinitions()[runningBuild.build] ?: return branchConfig
-        return definition.applyTo(branchConfig)
-    }
+    ): BranchConfig =
+        configLoader
+            .loadForWorktree(workingDir, worktree)
+            .buildSettings(runningBuild.branch, runningBuild.build)
 
     private class ActiveBuild(
         val runningBuild: RunningBuild,

src/main/kotlin/de/hoennig/gittally/config/GitTallyConfig.kt

@@ -21,6 +21,22 @@ data class GitTallyConfig(
     /** The configured [buildDefinitions] plus the implicit `default` build unless overridden. */
     fun effectiveBuildDefinitions(): Map<String, BuildDefinition> =
         mapOf(BuildDefinition.DEFAULT to BuildDefinition(onPush = true)) + buildDefinitions
+
+    /**
+     * The settings one build of [build] on [branch] runs with: the branch entry (falling
+     * back to `branches.default`) with the build definition's overrides applied last.
+     * A build name without a definition — a job removed from the config since the run —
+     * falls back to the plain branch settings.
+     * This must stay the single answer to "what does this build run", used by the
+     * executor and by everything that displays it.
+     */
+    fun buildSettings(
+        branch: String,
+        build: String,
+    ): BranchConfig {
+        val branchConfig = branches[branch] ?: branches["default"] ?: BranchConfig()
+        return effectiveBuildDefinitions()[build]?.applyTo(branchConfig) ?: branchConfig
+    }
 }
 
 data class ServerConfig(

src/main/kotlin/de/hoennig/gittally/server/UiController.kt

@@ -6,7 +6,9 @@ import de.hoennig.gittally.build.BuildResult
 import de.hoennig.gittally.build.BuildResultRepository
 import de.hoennig.gittally.build.BuildStatus
 import de.hoennig.gittally.config.ConfigLoader
+import de.hoennig.gittally.git.GitService
 import de.hoennig.gittally.metrics.SystemMetricsCollector
+import de.hoennig.gittally.watcher.Watcher
 import jakarta.servlet.http.HttpServletRequest
 import org.springframework.beans.factory.ObjectProvider
 import org.springframework.boot.info.BuildProperties
@@ -36,6 +38,7 @@ class UiController(
     private val buildExecutor: BuildExecutor,
     private val artifactStore: ArtifactStore,
     private val configLoader: ConfigLoader,
+    private val gitService: GitService,
     private val metricsCollector: SystemMetricsCollector,
     private val branchListing: BranchListing,
     private val branchPermalinks: BranchPermalinks,
@@ -189,7 +192,7 @@ class UiController(
         model.addAttribute("filesBase", filesBase)
         model.addAttribute("result", result?.let { BuildRowView.from(it, links) })
         model.addAttribute("hasArtifacts", artifactDir != null)
-        model.addAttribute("buildCommand", result?.let { branchBuildCommand(it.branch) })
+        model.addAttribute("buildCommand", result?.let { buildCommandOf(it) })
         model.addAttribute(
             "logs",
             artifactDir?.let { logFiles(it, scanForFailure = result != null && result.status != BuildStatus.SUCCESS) }
@@ -220,10 +223,24 @@ class UiController(
         return links
     }
 
-    /** The currently configured build command — the command actually used at build time is not persisted. */
-    private fun branchBuildCommand(branch: String): String {
-        val branches = configLoader.load(workingDir).branches
-        return (branches[branch] ?: branches["default"])?.buildCommand ?: ""
+    /**
+     * The command this build runs, resolved exactly like the executor resolves it: the
+     * branch layer committed at the build's own commit, plus the overrides of the build
+     * definition it belongs to. Reading only the primary config would show a command no
+     * build of this pool ever ran — the branch and its job usually override it.
+     * The command used by a past run is not persisted, so this is the current answer.
+     */
+    private fun buildCommandOf(result: BuildResult): String {
+        val config =
+            try {
+                configLoader.loadWithBranchLayer(
+                    workingDir,
+                    gitService.showFileAtCommit(result.commit, Watcher.CONFIG_FILE, workingDir),
+                )
+            } catch (_: Exception) {
+                configLoader.load(workingDir)
+            }
+        return config.buildSettings(result.branch, result.build).buildCommand
     }
 
     /**

src/main/resources/templates/artifact.html

@@ -39,7 +39,7 @@
             <li>Started: <span th:text="${result.startedAt}">2026-07-07 12:00</span>
                 <th:block th:if="${result.duration != ''}">— Duration: <span th:text="${result.duration}">1:23</span></th:block>
             </li>
-            <li th:if="${buildCommand != null}">Build command (as currently configured):<br>
+            <li th:if="${buildCommand != null}">Build command (as configured for this build):<br>
                 <code th:text="${buildCommand}">./gradlew test</code>
             </li>
         </ul>

src/test/kotlin/de/hoennig/gittally/server/PermanentBranchRoutesTest.kt

@@ -8,6 +8,7 @@ import de.hoennig.gittally.build.BuildResultRepository
 import de.hoennig.gittally.build.BuildStatus
 import de.hoennig.gittally.config.ConfigLoader
 import de.hoennig.gittally.config.GitTallyConfig
+import de.hoennig.gittally.git.GitService
 import de.hoennig.gittally.metrics.SystemMetricsCollector
 import io.kotest.core.spec.style.FunSpec
 import io.mockk.clearMocks
@@ -52,6 +53,9 @@ class PermanentBranchRoutesTest : FunSpec() {
     @MockkBean
     lateinit var configLoader: ConfigLoader
 
+    @MockkBean
+    lateinit var gitService: GitService
+
     @MockkBean
     lateinit var metricsCollector: SystemMetricsCollector
 
@@ -81,11 +85,14 @@ class PermanentBranchRoutesTest : FunSpec() {
                 artifactStore,
                 controlTokens,
                 configLoader,
+                gitService,
                 metricsCollector,
                 branchListing,
                 branchPermalinks,
             )
             every { configLoader.load(any()) } returns GitTallyConfig()
+            every { configLoader.loadWithBranchLayer(any(), anyNullable()) } returns GitTallyConfig()
+            every { gitService.showFileAtCommit(any(), any(), any()) } returns null
             every { controlTokens.token() } returns "test-token"
             every { branchListing.branches(any()) } returns emptyList()
             every { branchPermalinks.latestGreenBuild("main") } returns greenBuild

src/test/kotlin/de/hoennig/gittally/server/UiControllerTest.kt

@@ -7,10 +7,13 @@ import de.hoennig.gittally.build.BuildResult
 import de.hoennig.gittally.build.BuildResultRepository
 import de.hoennig.gittally.build.BuildStatus
 import de.hoennig.gittally.build.RunningBuild
+import de.hoennig.gittally.config.BranchConfig
+import de.hoennig.gittally.config.BuildDefinition
 import de.hoennig.gittally.config.ConfigLoader
 import de.hoennig.gittally.config.GitTallyConfig
 import de.hoennig.gittally.config.GiteaConfig
 import de.hoennig.gittally.config.ServerConfig
+import de.hoennig.gittally.git.GitService
 import de.hoennig.gittally.metrics.MetricAggregate
 import de.hoennig.gittally.metrics.SystemMetrics
 import de.hoennig.gittally.metrics.SystemMetricsCollector
@@ -58,6 +61,9 @@ class UiControllerTest : FunSpec() {
     @MockkBean
     lateinit var configLoader: ConfigLoader
 
+    @MockkBean
+    lateinit var gitService: GitService
+
     @MockkBean
     lateinit var metricsCollector: SystemMetricsCollector
 
@@ -103,6 +109,7 @@ class UiControllerTest : FunSpec() {
                 artifactStore,
                 controlTokens,
                 configLoader,
+                gitService,
                 metricsCollector,
                 branchListing,
                 branchPermalinks,
@@ -112,6 +119,8 @@ class UiControllerTest : FunSpec() {
                     server = ServerConfig(impressumUrl = "https://example.org/imprint"),
                     gitea = GiteaConfig(baseUrl = "https://git.example.org", owner = "acme", repo = "widget"),
                 )
+            every { configLoader.loadWithBranchLayer(any(), anyNullable()) } returns GitTallyConfig()
+            every { gitService.showFileAtCommit(any(), any(), any()) } returns null
             every { controlTokens.token() } returns "test-token"
             every { repository.latestGreenFor(any()) } returns null
         }
@@ -264,6 +273,28 @@ class UiControllerTest : FunSpec() {
                 ).andExpect(content().string(not(containsString("reports/tests/test/packages/index.html"))))
         }
 
+        test("the artifact page shows the command of the build's own definition, not the plain branch command") {
+            val pitestResult =
+                successResult.copy(
+                    build = "pitest",
+                    name = "main@pitest",
+                    artifactKey = "main-pitest-key",
+                )
+            every { repository.history() } returns listOf(pitestResult)
+            every { artifactStore.artifactDir("main-pitest-key") } returns null
+            every { configLoader.loadWithBranchLayer(any(), anyNullable()) } returns
+                GitTallyConfig(
+                    branches = mapOf("default" to BranchConfig(buildCommand = "./gradlew quick-check")),
+                    buildDefinitions = mapOf("pitest" to BuildDefinition(buildCommand = "./gradlew pitestFull")),
+                )
+
+            mockMvc
+                .perform(get("/builds/main-pitest-key"))
+                .andExpect(status().isOk)
+                .andExpect(content().string(containsString("./gradlew pitestFull")))
+                .andExpect(content().string(not(containsString("./gradlew quick-check"))))
+        }
+
         test("artifact index links a single index-less report page as a directory, keeping the URL stable") {
             val artifactDir = Files.createDirectories(tempDir.resolve("main-abc123-key"))
             Files.createDirectories(artifactDir.resolve("reports/profile"))