The ‘hammer show’ command can be used to dump the B-Tree structure of a Hammer volume, and CRC errors can be spotted.  It’s rare that anyone would need it, but if you do, this dumped information will include file hierarchy information.

If that makes you a bit nervous to repost any of that information when talking about it in public, Tomohiro Kusumi has added an ‘obfuscate’ option to ‘hammer show’ that does just that – it hides path information from the debug output.