Deployment Arguments via dfx.json

Is args supposed to be working in dfx 0.17.0? I don’t think I’ve ever had this work actually:

        "evm_rpc": {
            "type": "custom",
            "candid": "https://github.com/internet-computer-protocol/ic-eth-rpc/releases/latest/download/evm_rpc.did",
            "wasm": "https://github.com/internet-computer-protocol/ic-eth-rpc/releases/latest/download/evm_rpc_dev.wasm.gz",
            "specified_id": "be2us-64aaa-aaaaa-qaabq-cai",
            "args": "(record { nodesInSubnet = 28 })",
            "remote": {
                "id": {
                    "ic": "a6d44-nyaaa-aaaap-abp7q-cai"
                }
            }
        }

With dfx deploy I get

Installing canisters...
Error: Failed while trying to deploy canisters.
Caused by: Failed while trying to deploy canisters.
  Failed while trying to install all canisters.
    Failed to install wasm module to canister 'evm_rpc'.
      Failed to create argument blob.
        Invalid data: Expected arguments but found none.