4 files changed, 6 insertions, 33 deletions
diff --git a/src/dotty/tools/dotc/core/Contexts.scala b/src/dotty/tools/dotc/core/Contexts.scala
index 635390ef5..b11e77ef2 100644
--- a/src/dotty/tools/dotc/core/Contexts.scala
+++ b/src/dotty/tools/dotc/core/Contexts.scala
@@ -170,7 +170,11 @@ object Contexts {
       if (implicitsCache == null )
         implicitsCache = {
           val implicitRefs: List[TermRef] =
-            if (isClassDefContext) owner.thisType.implicitMembers
+            if (isClassDefContext) 
+              try owner.thisType.implicitMembers
+              catch {
+                case ex: CyclicReference => Nil
+              }
             else if (isImportContext) importInfo.importedImplicits
             else if (isNonEmptyScopeContext) scope.implicitDecls
             else Nil
diff --git a/src/dotty/tools/dotc/core/Types.scala b/src/dotty/tools/dotc/core/Types.scala
index 141b29ab7..b8e0a48c1 100644
--- a/src/dotty/tools/dotc/core/Types.scala
+++ b/src/dotty/tools/dotc/core/Types.scala
@@ -2976,7 +2976,7 @@ object Types {
       val ex = new CyclicReference(denot)
       if (!(ctx.mode is typer.Mode.CheckCyclic)) {
         cyclicErrors.println(ex.getMessage)
-        for (elem <- ex.getStackTrace take 40)
+        for (elem <- ex.getStackTrace take 50)
           cyclicErrors.println(elem.toString)
       }
       ex
diff --git a/tests/new/S5.scala b/tests/new/S5.scala
deleted file mode 100644
index ba87869a1..000000000
--- a/tests/new/S5.scala
+++ /dev/null
@@ -1,31 +0,0 @@
-/* Original comment:
- * Here's a fragment of a Scala encoding for the Keris module system;
-** the compiler claims:
-**
-** S5.scala:28: value n in class N of type N.this._N.n
-** cannot override value n in class M of type M.this._N.n
-**        val system = new M() with N() {}
-**                         ^
-** To me it seems like the code is perfectly fine...
-*/
-abstract class M() {
-    val _N: N;
-    val n: _N.n;
-    val _M: M = this;
-    val m: _M.m = new _M.m();
-    class m() {
-        // module body of M
-    }
-}
-trait N {
-    val _N: N = this;
-    val n: _N.n = new _N.n();
-    val _M: M;
-    val m: _M.m;
-    class n() {
-        // module body of N
-    }
-}
-object O {
-    val system = new M() with N {}
-}
diff --git a/tests/pending/pos/SI-7638.scala b/tests/pos/SI-7638.scala
index ed581efe9..ed581efe9 100644
--- a/tests/pending/pos/SI-7638.scala
+++ b/tests/pos/SI-7638.scala