I have encountered some strange behaviour when using pod() with keys that are tables.

This code snippet prints {} (it should print nil if it were to be consistent with other pod behaviour)

local a = {}
a[a] = 1

?pod(a)

This code snippet also prints {}

local a = {}
local b = {}
a[b] = 2

?pod(a)

But now, the strange part. This:

local a = {}
local b = {}
a[a] = 1
a[b] = 2

?pod(a)

causes an error, it reads simply attempt to compare two table values. No error location, just this!