incompatibility between zeroHashes and custom hash function

[olegrok]

In case you want to provide custom hash function behavior can be quite unexpected.

It happens because zeroHashes is global variable that is initialized by default with sha256:

fastssz/hasher.go

Line 39 in f43e88e

zeroHashes[i+1] = sha256.Sum256(tmp[:])

[ferranbt]

Hi, what is your use case for a custom hash function?

[olegrok]

Hi! I want to use poseidon hash instead of sha256