snapshot 17w43a / MacOS / my sound files are missing

Preparing to launch minecraft client for 17w43a
07:20:38 launcher Checking installations.
07:20:38 launcher Minecraft client 17w43a is ready to start.
07:20:38 launcher Starting!
07:20:38 launcher Using default game log configuration client-1.12.xml (outputs XML)
07:20:39 bjh Setting user: jplong
07:20:40 bjh LWJGL Version: 3.1.2 build 29
07:20:41 qf Reloading ResourceManager: Default, Default 32x32 Snapshot
07:20:41 cih Missing sound for event: minecraft:ambient.cave
07:20:41 cih Missing sound for event: minecraft:block.anvil.break
07:20:41 cih Missing sound for event: minecraft:block.anvil.destroy
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