Print yet more info to find Heisenbugs.

Author: odersky

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

@@ -205,17 +205,23 @@ object Denotations {
           denot.symbol
       }
 
+    def slowSearch(name: Name)(implicit ctx: Context): Symbol =
+      info.decls.find(_.name == name).getOrElse(NoSymbol)
+
     def requiredMethod(name: PreName)(implicit ctx: Context): TermSymbol =
       if (info.exists) {
         val meth = info.member(name.toTermName)
         if (meth.exists) meth.requiredSymbol(_ is Method).asTerm
         else { // Heisenbughunt
-          println(s"*** missing method: $name in $this")
-          println(info.decls)
+          println(s"*** missing method: ${name.toString} in $this")
+          info.decls.checkConsistent()
+          println(i"decls = ${info.decls}")
+          if (slowSearch(name.toTermName).exists)
+            System.err.println(i"**** slow search found: ${slowSearch(name.toTermName)}")
           throw new TypeError(s"Missing method: $this . $name")
         }
       }
-      else throw new TypeError(s"Missing module: $this")
+      else throw new TypeError(s"M  issing module: $this")
 
     def requiredMethodRef(name: PreName)(implicit ctx: Context): TermRef =
       requiredMethod(name).termRef