When building the 1.6.4 build from Gradle, I get this crash report. Is this reproducible?
http://pastebin.com/DwCdhFRZ

I was building my separate fork, but I also tested this with the latest 1.6.4 build.

EDIT:
Just to be clear, it's throwing a NoSuchFieldError on startup, that can be traced back to the declaration of the numUsingPlayer count inside TileAlchemicalChest.

Have you read the crash report? There's no field called "field_76245_d". Which is most likely a pre-generated method inside of the AlchemicalChest class.

1. Are you sure you used the 1.6.4 branch? 2. If yes, make sure you ran 'gradle build' (not 'gralde jar'!) 3. Still not fixed? It's an obfuscation problem then. Make sure you setup is up to date (run 'gradle cleanCache' to reset setup).

Hexish, that's why I was confused. I searched the code for such a field and found nothing.

Dynious, I did use the 1.6.4 branch (I'm sure because I was messing with Aludel recipes), I did use "gradle build", and made sure to update my MCP environment. I'll get back to you on how the cleanCache works.

EDIT:
I tried cleaning the cache and building it again - same error. I assume I'm the only one to get this, so it's probably something to do with my build environment.

0x277F neither did I, weird.

Any ideas on what might be wrong with my build environment?

Minecraft may be calling a method field_76245_d for some reason, as most methods and variables in this damn code is either func_... or field_...

Damn you, Minecraft obfuscation.
I decompiled a 1.6.4 jar using Fernflower myself, but couldn't find any matching fields with Eclipse.