`bid_scraper_client` EPROTO error with Builder Playground

[emlautarom1]

Steps to reproduce:

• Run builder-playground as follows:

cd builder-playground
go run main.go cook l1

• Run rbuilder as follows:

cd rbuilder
sed -i "s|\$HOME|$HOME|g" config-playground.toml
# Had to also make this edits since some configs are out-of-date
sed -i "s|data_reth|volume-el-data|g" config-playground.toml
sed -i "s|reth.ipc|volume-el-data/reth.ipc|g" config-playground.toml
cargo run --bin rbuilder run config-playground.toml

Actual behavior:

Almost immediately I start seeing the following errors being logged:

2025-08-11T21:11:23.139245Z ERROR bid_scraper::bid_scraper_client: Subscriber returned an error url="tcp://0.0.0.0:5555" error=Errno(EPROTO)

Current setup:

• rbuilder: https://github.com/flashbots/rbuilder/tree/ac093f11fe958e5490746ff6b8252c4fb8acd991
• builder-playground: https://github.com/flashbots/builder-playground/tree/b2cf72f73a14bdb326ff5e7bcb7101b6139557c2
• Linux (Fedora Workstation 42)

Logs

logs.txt