Constant zebra_rpc::methods::get_block_template_rpcs::constants::NOT_SYNCED_ERROR_CODE

pub const NOT_SYNCED_ERROR_CODE: ErrorCode;

The RPC error code used by zcashd for when it’s still downloading initial blocks.

s-nomp mining pool expects error code -10 when the node is not synced: https://github.com/s-nomp/node-stratum-pool/blob/d86ae73f8ff968d9355bb61aac05e0ebef36ccb5/lib/pool.js#L142