diff -r 356eaea05bf0 -r 68fa3d4026ea test/jdk/java/net/httpclient/MockServer.java
--- a/test/jdk/java/net/httpclient/MockServer.java	Mon Jun 25 21:22:16 2018 +0300
+++ b/test/jdk/java/net/httpclient/MockServer.java	Mon Jun 25 13:41:39 2018 -0700
@@ -183,7 +183,8 @@
             } catch (IOException |InterruptedException e1) {
                 cleanup();
             } catch (Throwable t) {
-                System.out.println("X: " + t);
+                System.out.println("Exception: " + t);
+                t.printStackTrace();
                 cleanup();
             }
         }