Add unexpected error variant

beacon_node/beacon_chain/src/block_production/gloas.rs

@@ -692,11 +692,8 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                         ));
                     }
                 }
-                // TODO(gloas) we should never receive a blinded response.
-                // Should return some type of `Unexpected` error variant as this should never happen
-                // in the V4 block production flow
                 BlockProposalContentsType::Blinded(_) => {
-                    return Err(BlockProductionError::GloasNotImplemented);
+                    return Err(BlockProductionError::Unexpected("Should never produce a blinded block post-Gloas".to_owned()));
                 }
             };
 

beacon_node/beacon_chain/src/errors.rs

@@ -321,6 +321,7 @@ pub enum BlockProductionError {
     SszTypesError(ssz_types::Error),
     // TODO(gloas): Remove this once Gloas is implemented
     GloasNotImplemented,
+    Unexpected(String),
 }
 
 easy_from_to!(BlockProcessingError, BlockProductionError);