Steps to Reproduce the Bug

Boot Minecraft with just Fabric API & JEI installed.
Left Click/Right Click/R/U key while hovering over empty inventory slot.

Expected Behavior

Nothing should be written to log.

Actual Behavior

The log receives two of this warning:
[Render thread/WARN]: Ignoring invalid ingredient: 0 air minecraft:air

Mod Pack URL (Optional)

No response

Mod Pack Version (Optional)

No response

Extra Notes (Optional)

This bug is also present in 15.10.0.35.

latest.log

https://gist.github.com/Sansomeness/f33e6427efd2386e747ce32274c19d2a

This appears to be an issue in 1.21 NeoForge as well.

JEI 19.7.0.90
NeoForge 21.0.163

I have pushed fixes for this on 1.21 and 1.20.1

Thanks for the report!
This is pretty excessive and not what I intended, I'll remove this log.