I was trying to figure out why some float values where becoming NaN values in the Godot debugger. However, according to the debugger the values of the variables in question were always 0 or 1 as expected.

After adding an explicit check, I found that the debugger was lying to me. Apparently, this bug in the debugger is already tracked at godotengine/godot#88006. This is worthy of being listed as a Godot crime