--- a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.printer/src/org/graalvm/compiler/printer/BinaryGraphPrinter.java	Tue Apr 23 14:09:54 2019 -0400
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.printer/src/org/graalvm/compiler/printer/BinaryGraphPrinter.java	Tue Apr 23 22:55:09 2019 +0200
@@ -69,6 +69,7 @@
 import org.graalvm.compiler.phases.schedule.SchedulePhase;
 import org.graalvm.graphio.GraphBlocks;
 import org.graalvm.graphio.GraphElements;
+import org.graalvm.graphio.GraphLocations;
 import org.graalvm.graphio.GraphOutput;
 import org.graalvm.graphio.GraphStructure;
 import org.graalvm.graphio.GraphTypes;
@@ -77,7 +78,6 @@
 import jdk.vm.ci.meta.ResolvedJavaField;
 import jdk.vm.ci.meta.ResolvedJavaMethod;
 import jdk.vm.ci.meta.Signature;
-import org.graalvm.graphio.GraphLocations;
 
 public class BinaryGraphPrinter implements
                 GraphStructure<BinaryGraphPrinter.GraphInfo, Node, NodeClass<?>, Edges>,
@@ -528,7 +528,7 @@
             public URI getURI() {
                 String path = e.getFileName();
                 try {
-                    return path == null ? null : new URI(null, null, path, null);
+                    return new URI(null, null, path == null ? "(Unknown Source)" : path, null);
                 } catch (URISyntaxException ex) {
                     throw new IllegalArgumentException(ex);
                 }