Overview

Hello erigon developers.

I'm running a separate Pectra PoS testnet chain for API testing. During testing, I observed discrepancies in the JSON-RPC responses from execution clients—geth, besu, nethermind, reth and erigon. Specifically, when calling debug_getBadBlocks, erigon will return null if no bad blocks recently, while other EL clients return []. Accroding to the spec, the results should be array.

{"id": 1, "jsonrpc": "2.0", "result": []}
{"id": 1, "jsonrpc": "2.0", "result": []}
{"id": 1, "jsonrpc": "2.0", "result": []}
{"id": 1, "jsonrpc": "2.0", "result": []}
{"id": 1, "jsonrpc": "2.0", "result": null}

I've pushed a PR for this and this is my first PR for erigon, thanks for your attention!

System information

Client versions

• erigon/3.1.0/linux-amd64/go1.24.7
• Nethermind/v1.33.1+cda59e5b/linux-x64/dotnet9.0.8
• besu/v25.8.0/linux-x86_64/openjdk-java-21
• Geth/v1.16.3-stable-d818a9af/linux-amd64/go1.24.6
• reth/v1.7.0-9d56da5/x86_64-unknown-linux-gnu

with

• Prysm/v6.0.4 (linux amd64)

Chain/Network: private Pectra testnet

Expected behaviour

Return empty []

Actual behaviour

Return null

Steps to reproduce the behaviour

curl POST http://127.0.0.1:5508 \
   -H "Content-Type: application/json" \
   -d '
{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "debug_getBadBlocks",
  "params": []
}
'