Filecoin now uses different bitwidths for different HAMTs

[Stebalien]

go-ipld-adl-hamt/node.go

Lines 36 to 38 in b2c8ddb

	if n.modeFilecoin {
	return 5
	}

[mvdan]

Thanks for the heads up! What version of filecoin has this characteristic, and where is it documented?

At the time the code was written I was following the stable and in-use version of Filecoin's HAMT, which I think was actors v3:

go-ipld-adl-hamt/filecoin_test.go

Line 9 in b2c8ddb

// fhamt "github.com/filecoin-project/go-hamt-ipld/v3"

[Stebalien]

Since actors v3, HAMT v3. Take a look at the AsMap calls in specs-actors.