Better test.

sbt/src/sbt-test/dependency-management/force/project/TestProject.scala

@@ -5,17 +5,22 @@ object TestProject extends Build
 {
 	lazy val root = Project("root", file(".")) settings(
 		ivyPaths <<= (baseDirectory, target)( (dir, t) => new IvyPaths(dir, Some(t / "ivy-cache"))),
-		libraryDependencies ++= Seq("log4j" % "log4j" % "1.2.14" force(),
- 																"log4j" % "log4j" % "1.2.13"),
-		TaskKey[Unit]("check-forced") <<= check()
+		libraryDependencies <++= baseDirectory (libraryDeps),
+		TaskKey[Unit]("check-forced") <<= check("1.2.14"),
+		TaskKey[Unit]("check-depend") <<= check("1.2.13")
 	)
 
-	def check() =
+	def libraryDeps(base: File) = {
+		val slf4j = Seq("org.slf4j" % "slf4j-log4j12" % "1.1.0")  // Uses log4j 1.2.13
+		if ((base / "force").exists) slf4j :+ ("log4j" % "log4j" % "1.2.14" force()) else slf4j
+	}
+
+	def check(ver: String) =
 		(dependencyClasspath in Compile) map { jars =>
 			val log4j = jars map (_.data) collect {
-				case f if f.getName contains "log4j" => f.getName
+				case f if f.getName contains "log4j-" => f.getName
 			}
-			if (log4j.size != 1 || !log4j.head.contains("1.2.14"))
+			if (log4j.size != 1 || !log4j.head.contains(ver))
   			error("Did not download the correct jar.")
 		}
 }

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

@@ -1 +1,15 @@
-> check-forced
+#$ pause
+$ touch force
+
+#$ pause
+> reload
+#$ pause
+
+> check-forced
+-> check-depend
+
+$ delete force
+> reload
+
+-> check-forced
+> check-depend