Add forceUpdateMs

main/src/main/scala/sbt/Defaults.scala

@@ -115,7 +115,8 @@ object Defaults extends BuildCommon {
       pomPostProcess :== idFun,
       pomAllRepositories :== false,
       pomIncludeRepository :== Classpaths.defaultRepositoryFilter,
-      updateOptions := UpdateOptions()
+      updateOptions := UpdateOptions(),
+      forceUpdateMs :== None
     )
 
   /** Core non-plugin settings for sbt builds.  These *must* be on every build or the sbt engine will fail to run at all. */
@@ -1324,7 +1325,13 @@ object Classpaths {
   def updateTask: Initialize[Task[UpdateReport]] = Def.task {
     val depsUpdated = transitiveUpdate.value.exists(!_.stats.cached)
     val isRoot = executionRoots.value contains resolvedScoped.value
+    val forceUpdate = forceUpdateMs.value
     val s = streams.value
+    val fullUpdateOutput = s.cacheDirectory / "out"
+    val forceUpdateByTime = forceUpdate match {
+      case None         => false
+      case Some(period) => fullUpdateOutput.exists() && fullUpdateOutput.lastModified() <= (System.currentTimeMillis() - period)
+    }
     val scalaProvider = appConfiguration.value.provider.scalaProvider
 
     // Only substitute unmanaged jars for managed jars when the major.minor parts of the versions the same for:
@@ -1360,7 +1367,7 @@ object Classpaths {
       if (executionRoots.value exists { _.key == evicted.key }) EvictionWarningOptions.empty
       else (evictionWarningOptions in update).value
     cachedUpdate(s.cacheDirectory / updateCacheName.value, show, ivyModule.value, uc, transform,
-      skip = (skip in update).value, force = isRoot, depsUpdated = depsUpdated,
+      skip = (skip in update).value, force = isRoot || forceUpdateByTime, depsUpdated = depsUpdated,
       uwConfig = uwConfig, logicalClock = logicalClock, depDir = Some(depDir),
       ewo = ewo, log = s.log)
   }

main/src/main/scala/sbt/Keys.scala

@@ -324,6 +324,7 @@ object Keys {
   val publishArtifact = SettingKey[Boolean]("publish-artifact", "Enables (true) or disables (false) publishing an artifact.", AMinusSetting)
   val packagedArtifact = TaskKey[(Artifact, File)]("packaged-artifact", "Generates a packaged artifact, returning the Artifact and the produced File.", CTask)
   val checksums = SettingKey[Seq[String]]("checksums", "The list of checksums to generate and to verify for dependencies.", BSetting)
+  val forceUpdateMs = SettingKey[Option[Long]]("force-update-ms", "Amount of time in milliseconds after which to force a full update to occur", CSetting)
 
   val classifiersModule = TaskKey[GetClassifiersModule]("classifiers-module", rank = CTask)
   val conflictWarning = SettingKey[ConflictWarning]("conflict-warning", "Configures warnings for conflicts in dependency management.", CSetting)

notes/0.13.9/forceupdatems.markdown

@@ -0,0 +1,9 @@
+  [@ajsquared]: https://github.com/ajsquared
+
+
+### Changes with compatibility implications
+
+### Improvements
+- Adds `forceUpdateMs` key, that takes values of `Option[Long]` representing a number of milliseconds.  If set, a full `update` will occur after that amount of time without needing to explicitly run the `update` task.
+
+### Fixes

sbt/src/sbt-test/dependency-management/force-update-ms/build.sbt

@@ -0,0 +1,13 @@
+libraryDependencies += "log4j" % "log4j" % "1.2.16" % "compile"
+
+autoScalaLibrary := false
+
+TaskKey[Unit]("check-last-update-time") <<= streams map { (s) =>
+  val fullUpdateOutput = s.cacheDirectory / "out"
+  val timeDiff = System.currentTimeMillis()-fullUpdateOutput.lastModified()
+  val exists = fullUpdateOutput.exists()
+  s.log.info(s"Amount of time since last full update: $timeDiff")
+  if (exists && timeDiff > 5000) {
+    sys.error("Full update not perfomed")
+  }
+}

sbt/src/sbt-test/dependency-management/force-update-ms/test

@@ -0,0 +1,11 @@
+$ absent target/resolution-cache
+> compile
+$ exists target/resolution-cache
+> checkLastUpdateTime
+$ sleep 10000
+> compile
+# This is expected to fail
+-> checkLastUpdateTime
+> set forceUpdateMs := Some(5000)
+> compile
+> checkLastUpdateTime