The following code causes a segmentation fault when compiled in bytecode (not in native):

let rec f =
	let [| f0 |] = [| 0 |] in
	function
	| 0 -> f0
	| n -> f (n - 1)

let _ = f 1

Even weirder, the issue still stands when replacing the code by this:

let rec f =
	let 0 = 0 in
	function
	| 0 -> 0
	| n -> f (n - 1)

let _ = f 1

It seems the conjunction of a non-exhaustive pattern-matching and a let rec doesn't work very well. To be fair, the manual only describes the case let rec f = let x = _ in _, and not the case where x is replaced by a pattern, but it seems that replacing it by any exhaustive non-constructor pattern (tuples, records, polymorphic variant, lazy) causes no such issue.