- Better error reporting in `ReplApplyHandler`

- Logger now prints a newline when transitioning to ticker-mode, to avoid over-writing anything on the current line
- Consolidate `scalalib.Module` logic around `assemblyClasspath`

2 files changed, 28 insertions, 2 deletions

diff --git a/core/src/main/scala/mill/main/ReplApplyHandler.scala b/core/src/main/scala/mill/main/ReplApplyHandler.scala
index 7ce00f67..d4236487 100644
--- a/core/src/main/scala/mill/main/ReplApplyHandler.scala
+++ b/core/src/main/scala/mill/main/ReplApplyHandler.scala
@@ -4,7 +4,7 @@ package mill.main
 import mill.define.Applicative.ApplyHandler
 import mill.define._
 import mill.discover.{Discovered, Mirror}
-import mill.eval.Evaluator
+import mill.eval.{Evaluator, Result}
 import mill.util.OSet
 
 import scala.collection.mutable
@@ -34,7 +34,31 @@ class ReplApplyHandler(pprinter0: pprint.PPrinter, evaluator: Evaluator[_]) exte
   // as the user enters more REPL commands and changes the classpath
   val classLoaderSig = Evaluator.classLoaderSig
   override def apply[V](t: Task[V]) = {
-    evaluator.evaluate(OSet(t)).values.head.asInstanceOf[V]
+    val res = evaluator.evaluate(OSet(t))
+    res.values match{
+      case Seq(head: V) => head
+      case Nil =>
+        val msg = new mutable.StringBuilder()
+        msg.append(res.failing.keyCount + " targets failed\n")
+        for((k, vs) <- res.failing.items){
+          msg.append(k match{
+            case Left(t) => "Anonymous Task\n"
+            case Right(k) => k.segments.render + "\n"
+          })
+
+          for(v <- vs){
+            v match{
+              case Result.Failure(m) => msg.append(m + "\n")
+              case Result.Exception(t, outerStack) =>
+                msg.append(
+                  t.toString + t.getStackTrace.dropRight(outerStack.length).map("\n    " + _).mkString + "\n"
+                )
+
+            }
+          }
+        }
+        throw new Exception(msg.toString)
+    }
   }
 
   val generatedEval = new EvalGenerated(evaluator)
diff --git a/core/src/main/scala/mill/util/Logger.scala b/core/src/main/scala/mill/util/Logger.scala
index 1cec82ff..b42cc907 100644
--- a/core/src/main/scala/mill/util/Logger.scala
+++ b/core/src/main/scala/mill/util/Logger.scala
@@ -89,6 +89,8 @@ case class PrintLogger(colored: Boolean,
       nav.clearLine(2)
       nav.left(9999)
       p.flush()
+    }else{
+      println()
     }
     lastLineTicker = true
     infoStream.println(colors.info()(s))