More info to trouble-shoot Heisenbugs

Trouble shoot the case of the missing newRefArray method.

Author: odersky

src/dotty/tools/dotc/core/Denotations.scala

@@ -208,16 +208,22 @@ object Denotations {
     def slowSearch(name: Name)(implicit ctx: Context): Symbol =
       info.decls.find(_.name == name).getOrElse(NoSymbol)
 
-    def requiredMethod(name: PreName)(implicit ctx: Context): TermSymbol =
+    def requiredMethod(pname: PreName)(implicit ctx: Context): TermSymbol =
       if (info.exists) {
-        val meth = info.member(name.toTermName)
+        val name = pname.toTermName
+        val meth = info.member(name)
         if (meth.exists) meth.requiredSymbol(_ is Method).asTerm
         else { // Heisenbughunt
-          println(s"*** missing method: ${name.toString} in $this")
+          println(s"*** missing method: $name in $this")
+          val own = info.decl(name)
+          if (own.exists) {
+            println(i"decl succeeded: $own")
+            return own.requiredSymbol(_ is Method).asTerm
+          }
           info.decls.checkConsistent()
           println(i"decls = ${info.decls}")
           if (slowSearch(name.toTermName).exists) {
-            System.err.println(i"**** slow search found: ${slowSearch(name.toTermName)}")
+            System.err.println(i"**** slow search found: ${slowSearch(name)}")
             System.err.println("scope entries found:")
             var e = info.decls.lastEntry
             while (e != null) {

src/dotty/tools/dotc/core/SymDenotations.scala

@@ -1514,7 +1514,7 @@ object SymDenotations {
         if (denots == null) {
           denots = computeNPMembersNamed(name, inherited)
           if (isFullyCompleted) memberCache.enter(name, denots)
-        } else if (Config.checkCacheMembersNamed) {
+        } else if (Config.checkCacheMembersNamed || name.toString == "newRefArray") {
           val denots1 = computeNPMembersNamed(name, inherited)
           assert(denots.exists == denots1.exists, s"cache inconsistency: cached: $denots, computed $denots1, name = $name, owner = $this")
         }