not sure if this is needed, but it might help fix the bug that I'm seeing.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@1594 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/FilePath.java

@@ -179,6 +179,8 @@ public final class FilePath implements Serializable {
                     public ClassLoader getClassLoader() {
                         return callable.getClass().getClassLoader();
                     }
+
+                    private static final long serialVersionUID = 1L;
                 });
             } catch (IOException e) {
                 // wrap it into a new IOException so that we get the caller's stack trace as well.