Genesis block not retrievable through eth_getBlockByNumber / eth_getBlockByHash

[raulk]

Original report: https://filecoinproject.slack.com/archives/C04JEJB82RY/p1677833154264019

Observation

$ curl --data '{"jsonrpc": "2.0", "id":1, "method": "eth_getBlockByNumber", "params": ["0x0",true] }' -H 'Content-Type:application/json' https://api.hyperspace.node.glif.io/rpc/v1

Returns an error:

$ {"jsonrpc":"2.0","id":1,"error":{"code":1,"message":"get block bafyreiaqpwbbyjo4a42saasj36kkrpv4tsherf2e7bvezkert2a7dhonoi: cbor input should be of type array"}}

But correctly retrieves the first block:

$ curl --data '{"jsonrpc": "2.0", "id":1, "method": "eth_getBlockByNumber", "params": ["0x1",true] }' -H 'Content-Type:application/json' https://api.hyperspace.node.glif.io/rpc/v1

However, Filecoin.ChainGetTipsetByHeight works:

$ curl --data '{"jsonrpc": "2.0", "id":1, "method": "Filecoin.ChainGetTipSetByHeight", "params": [0,null]}' -H 'Content-Type:application/json' https://api.hyperspace.node.glif.io/rpc/v1

{"jsonrpc":"2.0","result":{"Cids":[{"/":"bafy2bzacebqfpeylmrl4h3pq4ofbdj2bfbw2i45fuy6qm4wxcyebpsxhrpqhu"}],"Blocks":[{"Miner":"t00","Ticket":{"VRFProof":"ZA4LPiLg3ODL5gSxjI+5qIowATHNTwlxIADDrxC4X0M="},"ElectionProof":{"WinCount":0,"VRFProof":null},"BeaconEntries":[{"Round":0,"Data":"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA="}],"WinPoStProof":null,"Parents":[{"/":"bafyreiaqpwbbyjo4a42saasj36kkrpv4tsherf2e7bvezkert2a7dhonoi"}],"ParentWeight":"0","Height":0,"ParentStateRoot":{"/":"bafy2bzacedd6s23oi2zrc74vadn6rqx725svbrdl7wstgygasx6jb3tedt6x4"},"ParentMessageReceipts":{"/":"bafy2bzacedswlcz5ddgqnyo3sak3jmhmkxashisnlpq6ujgyhe4mlobzpnhs6"},"Messages":{"/":"bafy2bzacecmda75ovposbdateg7eyhwij65zklgyijgcjwynlklmqazpwlhba"},"BLSAggregate":null,"Timestamp":1673848800,"BlockSig":null,"ForkSignaling":0,"ParentBaseFee":"100000000"}],"Height":0},"id":1}

Impact

Explorers and graph traversal tools may error.

Resolution

Reproduce with a test and fix.