Fix error messages on resolving cross-built modules and re-enable relevant neg tests

1 files changed, 9 insertions, 1 deletions

diff --git a/core/src/main/scala/mill/Main.scala b/core/src/main/scala/mill/Main.scala
index 873feed2..1dbae4c3 100644
--- a/core/src/main/scala/mill/Main.scala
+++ b/core/src/main/scala/mill/Main.scala
@@ -100,7 +100,15 @@ object Main {
             }
 
           case Mirror.Segment.Cross(cross) =>
-            resolve(tail, hierarchy.crossChildren.get._2, obj, rest, remainingCrossSelectors, newRevSelectorsSoFar)
+            val Some((crossGen, childMirror)) = hierarchy.crossChildren
+            val crossOptions = crossGen(hierarchy.node(obj, remainingCrossSelectors))
+            if (crossOptions.contains(cross)){
+              resolve(tail, childMirror, obj, rest, remainingCrossSelectors, newRevSelectorsSoFar)
+            }else{
+              Left("Cannot resolve cross " + renderSelector(newRevSelectorsSoFar.reverse))
+            }
+
+
         }
 
       case Nil => Left("Selector cannot be empty")