Returning values from actions

Question

I am trying to return a value from an action as follows:

[[eosio::action("test2")]] int test2(int x)
{
  return x;
}

The code compiles correctly, and the ABI file shows the correct action return value data:

{
    "____comment": "This file was generated with eosio-abigen. DO NOT EDIT ",
    "version": "eosio::abi/1.2",
    "types": [],
    "structs": [
        {
            "name": "test2",
            "base": "",
            "fields": [
                {
                    "name": "x",
                    "type": "int32"
                }
            ]
        }
    ],
    "actions": [
        {
            "name": "test2",
            "type": "test2",
            "ricardian_contract": ""
        }
    ],
    "tables": [],
    "kv_tables": {},
    "ricardian_clauses": [],
    "variants": [],
    "action_results": [
        {
            "name": "test2",
            "result_type": "int32"
        }
    ]
}

However, when I try to set the contract, I get the error:

Error 3070003: Serialization Error Processing WASM
Error Details:
env.set_action_return_value unresolveable

I tried to activate the intrinsic protocol BUILTIN-ACTION_RETURN_VALUE when setting up the system contracts but I get the error message:

Error 3260000: Subjective exception thrown during block production
Error Details: protocol feature with digest '69b064c5178e2738e144ed6caa9349a3995370d78db29e494b3126ebd9111966' is unrecognized

Any ideas on what I'm doing wrong?

Answer 1

Can you call the below to activate ACTION_RETURN_VALUE

cleos push action eosio activate '["c3a6138c5061cf291310887c0b5c71fcaffeab90d5deb50d3b9e687cead45071"]'

It looks like you called activate with the description_digest and not the feature_digest.

curl -X POST http://localhost:8888/v1/producer/get_supported_protocol_features | jq -r

...
{                                                                                                                                      
    "feature_digest": "c3a6138c5061cf291310887c0b5c71fcaffeab90d5deb50d3b9e687cead45071",
    "subjective_restrictions": {
      "enabled": true,
      "preactivation_required": true,
      "earliest_allowed_activation_time": "1970-01-01T00:00:00.000"
    },
    "description_digest": "69b064c5178e2738e144ed6caa9349a3995370d78db29e494b3126ebd9111966",
    "dependencies": [],
    "protocol_feature_type": "builtin",
    "specification": [
      {
        "name": "builtin_feature_codename",
        "value": "ACTION_RETURN_VALUE"
      }
    ]
  }
...