.

Author: lihaoyi

core/eval/src/mill/eval/EvaluatorImpl.scala

@@ -271,7 +271,7 @@ final class EvaluatorImpl(
       serialCommandExec = serialCommandExec
     )
 
-    val allResults = evaluated.transitiveResults.iterator ++ selectiveResults
+    val allResults = evaluated.transitiveResults ++ selectiveResults
 
     @scala.annotation.nowarn("msg=cannot be checked at runtime")
     val watched = allResults.collect {
@@ -301,18 +301,16 @@ final class EvaluatorImpl(
           result.map(_.value).hashCode(),
           pretty
         ))
-    }.flatten.toSeq
+    }.flatten.toVector
 
-    for(newMetadata <- maybeNewMetadata) {
+    for (newMetadata <- maybeNewMetadata) {
       val failingTaskNames = allResults
-        .collect { case (t: Task.Named[_], r) if r.asSuccess.isEmpty => t.ctx.segments.render}
+        .collect { case (t: Task.Named[_], r) if r.asSuccess.isEmpty => t.ctx.segments.render }
         .toSet
 
-      selective.saveMetadata(
-        newMetadata.copy(forceRunTasks = failingTaskNames)
-      )
+      // For tasks that were not successful, force them to re-run next time even if not changed
+      selective.saveMetadata(newMetadata.copy(forceRunTasks = failingTaskNames))
     }
-    
 
     val errorStr = ExecutionResultsApi.formatFailing(evaluated)
     evaluated.transitiveFailing.size match {

integration/invalidation/selective-execution/src/SelectiveExecutionChangedCodeTests.scala

@@ -5,8 +5,6 @@ import scala.concurrent.duration._
 import utest._
 import utest.asserts.{RetryMax, RetryInterval}
 
-
-
 object SelectiveExecutionChangedCodeTests extends UtestIntegrationTestSuite {
   implicit val retryMax: RetryMax = RetryMax(120.seconds)
   implicit val retryInterval: RetryInterval = RetryInterval(1.seconds)

integration/invalidation/selective-execution/src/SelectiveExecutionChangedInputsTests.scala

@@ -5,8 +5,6 @@ import scala.concurrent.duration._
 import utest._
 import utest.asserts.{RetryMax, RetryInterval}
 
-
-
 object SelectiveExecutionChangedInputsTests extends UtestIntegrationTestSuite {
   implicit val retryMax: RetryMax = RetryMax(120.seconds)
   implicit val retryInterval: RetryInterval = RetryInterval(1.seconds)
@@ -82,4 +80,3 @@ object SelectiveExecutionChangedInputsTests extends UtestIntegrationTestSuite {
     }
   }
 }
-

integration/invalidation/selective-execution/src/SelectiveExecutionTests.scala

@@ -56,4 +56,3 @@ object SelectiveExecutionTests extends UtestIntegrationTestSuite {
     }
   }
 }
-

integration/invalidation/selective-execution/src/SelectiveExecutionWatchTests.scala

@@ -104,5 +104,45 @@ object SelectiveExecutionWatchTests extends UtestIntegrationTestSuite {
         }
       }
     }
+
+    // Make sure that if a task fail/skipped/aborted during `--watch`, next time we
+    // run things selectively we run that task again to help ensure that the user
+    // seeing no failures in the terminal really means there are no failures left
+    test("rerun-failures") - retry(1) {
+      integrationTest { tester =>
+        import tester._
+
+        modifyFile(
+          workspacePath / "build.mill",
+          _.replace(
+            "def fooCommand() = Task.Command {",
+            "def fooCommand() = Task.Command { sys.error(\"boom foo\")"
+          )
+            .replace(
+              "def barCommand() = Task.Command {",
+              "def barCommand() = Task.Command { sys.error(\"boom bar\")"
+            )
+        )
+
+        val spawned = spawn(("-j1", "--watch", "{foo.fooCommand,bar.barCommand}"))
+
+        assertEventually { spawned.err.text().contains("boom") }
+
+        spawned.clear()
+        modifyFile(workspacePath / "build.mill", _.replace("sys.error(\"boom foo\")", ""))
+
+        assertEventually {
+          spawned.out.text().contains("Computing fooCommand") &&
+          // Make sure `bar` re-runs here and blows up again, even though we didn't modify the
+          // task, so the user is aware there is still a remaining failure after fixing foo
+          spawned.err.text().contains("boom bar")
+        }
+
+        spawned.clear()
+        modifyFile(workspacePath / "build.mill", _.replace("sys.error(\"boom bar\")", ""))
+
+        assertEventually { spawned.out.text().contains("Computing barCommand") }
+      }
+    }
   }
 }