# electrs-next > Docker configuration for testing the `next` branch of electrs. Builds `romanz/bitcoin:locations` and `romanz/electrs:next` from source, starts a mainnet Bitcoin Core node and then runs the electrs indexer. Add relevant CLI flags in `docker-compose.yml` if you want to run testnet/regtest. The data dirs default to `./data/bitcoin` and `./data/electrs` relative to `docker-compose.yml` on the host. You can point these elsewhere by changing them in `docker-compose.yml` if you already have a copy of the blockchain. To run: ```shell git clone https://github.com/lukechilds/electrs-next.git cd electrs-next docker-compose up ```