delete usages of toSet for determinism (#1686)

* delete usages of toSet for determinism

* add formatting suggestion from code review

1 files changed, 7 insertions, 2 deletions

diff --git a/src/main/scala/firrtl/options/DependencyManager.scala b/src/main/scala/firrtl/options/DependencyManager.scala
index 910d44bb..ee6a7404 100644
--- a/src/main/scala/firrtl/options/DependencyManager.scala
+++ b/src/main/scala/firrtl/options/DependencyManager.scala
@@ -167,8 +167,13 @@ trait DependencyManager[A, B <: TransformLike[A] with DependencyAPI[B]] extends
         blacklist = _currentState,
 
         /* Explore all invalidated transforms **EXCEPT** the current transform! */
-        extractor = (p: B) => v.filter(p.invalidates).map(oToD(_)).toSet - oToD(p)))
-      .reverse
+        extractor = (p: B) => {
+          val filtered = new LinkedHashSet[Dependency[B]]
+          filtered ++= v.filter(p.invalidates).map(oToD(_))
+          filtered -= oToD(p)
+          filtered
+        })
+    ).reverse
   }
 
   /** Wrap a possible [[CyclicException]] thrown by a thunk in a [[DependencyManagerException]] */