jhat on heap dump produced by jmap -heap fails with exception:

...
Finding object size using Printezis bits and skipping over...
java.io.IOException: Unrecognized heap dump sub-record type: 79
at com.sun.tools.hat.internal.parser.HprofReader.readHeapDump(HprofReader.java:499)
at com.sun.tools.hat.internal.parser.HprofReader.read(HprofReader.java:238)
at com.sun.tools.hat.internal.parser.Reader.readFile(Reader.java:92)
at com.sun.tools.hat.Main.main(Main.java:159)