Lots of warnings in checking types with recursively defined constraints

After displaying the following error message, an infinite (or deep) recursive call of X10Context_c.constraintProjection occurred when compiling RefA.x10.

RefA.x10:15: Cannot access a non-static field or method, or refer to "this" or "super" from a static context.

Exception stack trace is:
(omitted)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:207)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:258)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:246)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:270)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:207)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:258)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:246)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:270)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:207)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:258)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:246)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:270)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:207)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:258)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:270)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:207)
at x10.types.X10Context_c.constraintProjection(X10Context_c.java:173)
at x10.types.X10TypeEnv_c.entails(X10TypeEnv_c.java:1169)
at x10.types.X10TypeEnv_c.typeEquals(X10TypeEnv_c.java:1039)
at x10.types.X10TypeEnv_c.isSubtype(X10TypeEnv_c.java:737)
at x10.types.X10TypeEnv_c.isSubtype(X10TypeEnv_c.java:672)
at x10.types.X10TypeSystem_c.isSubtype(X10TypeSystem_c.java:2208)
at x10.types.checker.Converter.attemptCoercion(Converter.java:96)
at x10.ast.X10Return_c.typeCheck(X10Return_c.java:206)
at polyglot.ast.JL_c.typeCheck(JL_c.java:180)
at polyglot.visit.TypeChecker.leaveCall(TypeChecker.java:106)
at x10.visit.X10TypeChecker.leaveCall(X10TypeChecker.java:101)
at polyglot.visit.ErrorHandlingVisitor.leaveCall(ErrorHandlingVisitor.java:141)
at polyglot.visit.ErrorHandlingVisitor.leave(ErrorHandlingVisitor.java:279)
at polyglot.visit.ContextVisitor.leave(ContextVisitor.java:140)
at polyglot.visit.NodeVisitor.visitEdgeNoOverride(NodeVisitor.java:258)
at polyglot.visit.NodeVisitor.visitEdge(NodeVisitor.java:217)
at polyglot.ast.Node_c.visitChild(Node_c.java:179)
at polyglot.ast.Node_c.visitList(Node_c.java:239)
at polyglot.ast.AbstractBlock_c.visitChildren(AbstractBlock_c.java:72)
at polyglot.ast.JL_c.visitChildren(JL_c.java:45)
at x10.extension.X10Del_c.visitChildren(X10Del_c.java:123)
at polyglot.visit.NodeVisitor.visitEdgeNoOverride(NodeVisitor.java:251)
at polyglot.visit.NodeVisitor.visitEdge(NodeVisitor.java:217)
at polyglot.ast.Node_c.visitChild(Node_c.java:179)
at x10.ast.X10MethodDecl_c.typeCheckOverride(X10MethodDecl_c.java:933)
at polyglot.ast.JL_c.typeCheckOverride(JL_c.java:161)
at x10.visit.X10TypeChecker.override(X10TypeChecker.java:53)
at polyglot.visit.NodeVisitor.visitEdge(NodeVisitor.java:214)
at polyglot.ast.Node_c.visitChild(Node_c.java:179)
at polyglot.ast.Node_c.visitList(Node_c.java:239)
at polyglot.ast.ClassBody_c.visitChildren(ClassBody_c.java:63)
at polyglot.ast.JL_c.visitChildren(JL_c.java:45)
at x10.extension.X10Del_c.visitChildren(X10Del_c.java:123)
at polyglot.visit.NodeVisitor.visitEdgeNoOverride(NodeVisitor.java:251)
at polyglot.visit.NodeVisitor.visitEdge(NodeVisitor.java:217)
at polyglot.ast.Node_c.visitChild(Node_c.java:179)
at polyglot.ast.ClassDecl_c.typeCheckBody(ClassDecl_c.java:415)
at x10.ast.X10ClassDecl_c.typeCheckOverride(X10ClassDecl_c.java:642)
at polyglot.ast.JL_c.typeCheckOverride(JL_c.java:161)
at x10.visit.X10TypeChecker.override(X10TypeChecker.java:53)
at polyglot.visit.NodeVisitor.visitEdge(NodeVisitor.java:214)
at polyglot.ast.Node_c.visitChild(Node_c.java:179)
at polyglot.ast.Node_c.visitList(Node_c.java:239)
at polyglot.ast.SourceFile_c.visitChildren(SourceFile_c.java:116)
at polyglot.ast.JL_c.visitChildren(JL_c.java:45)
at x10.extension.X10Del_c.visitChildren(X10Del_c.java:123)
at polyglot.visit.NodeVisitor.visitEdgeNoOverride(NodeVisitor.java:251)
at polyglot.visit.NodeVisitor.visitEdge(NodeVisitor.java:217)
at polyglot.ast.Node_c.visit(Node_c.java:183)
at polyglot.frontend.VisitorGoal.runTask(VisitorGoal.java:45)
at polyglot.frontend.Scheduler.runPass(Scheduler.java:325)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:102)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.AbstractGoal_c.run(AbstractGoal_c.java:49)
at polyglot.types.LazyRef_c.get(LazyRef_c.java:45)
at polyglot.frontend.Scheduler.attempt(Scheduler.java:237)
at polyglot.frontend.Scheduler.runToCompletion(Scheduler.java:174)
at polyglot.frontend.Scheduler.runToCompletion(Scheduler.java:160)
at polyglot.frontend.Compiler.compile(Compiler.java:166)
at polyglot.frontend.Compiler.compileFiles(Compiler.java:134)
at polyglot.main.Main.start(Main.java:119)
at polyglot.main.Main.start(Main.java:74)
at polyglot.main.Main.main(Main.java:166)