Can't spend script utxo

[Fiftyw3bs]

I'm trying to spend a utxo are at a script address, but I get the following error message:

      Error :
      -------
      (Slot {getSlot = 6},GenericFail "GYBuildTxException (GYBuildTxBodyErrorAutoBalance (TxBodyScriptExecutionError [(ScriptWitnessIndexTxIn 1,ScriptErrorEvaluationFailed (CekError An error has occurred:\nThe machine terminated because of an error, either from a built-in function or from an explicit use of 'error'.\nCaused by: (unConstrData\n              (B #fea400a92180e63e946ef879e35010ec4c7b622634949597f3584f7c))) [])]))")

I'm not sure what the cause of the issue is, but I best guess is that it may have something to do with the redeemer, as even replacing the validation logic with True doesn't help.

[effectfully]

The error message says that your code is calling unConstrData over a Data value that is constructed using the B constructor (rather than the Constr one), which is indeed an error. It is likely a business logic error rather than something going wrong on our side. I'll keep this issue open for a bit, but with this amount of info it'll get closed soon.

[effectfully]

as even replacing the validation logic with True doesn't help.

Hm, maybe I'm wrong. Could you please share the full code?

[Fiftyw3bs]

Below is the definition of the redeemer

data CommitterIsRequester = CommitterIsRequester 
                          { cirUser1 :: PubKeyHash
                          , cirUser2 :: PubKeyHash
                          , cirUser3 :: PubKeyHash
                          , cirTxOut :: TxOutRef
                          } deriving (Show, Prelude.Eq)
PlutusTx.unstableMakeIsData ''CommitterIsRequester
PlutusTx.makeLift ''CommitterIsRequester

data CommitterIsPerformer = CommitterIsPerformer 
                          { cipUser4 :: PubKeyHash
                          , cipTxOut :: TxOutRef
                          } deriving (Show, Prelude.Eq)
PlutusTx.unstableMakeIsData ''CommitterIsPerformer
PlutusTx.makeLift ''CommitterIsPerformer

data CommittedBy = RequesterCommitted CommitterIsRequester
                 | PerformerCommitted CommitterIsPerformer
                 deriving (Show, Prelude.Eq)
-- PlutusTx.makeIsDataIndexed ''CommittedBy [ ('RequesterCommitted, 9), ('PerformerCommitted, 10) ]
-- PlutusTx.makeLift ''CommittedBy
PlutusTx.unstableMakeIsData ''CommittedBy
PlutusTx.makeLift ''CommittedBy

data StepAction = Claim
                | Commit CommittedBy
                | Commence
                -- | Confirm
                | Delegate
                | Fulfill
                | Refund
                | InvokeConflictResolution PlutusV2.PubKeyHash
                | ResolveConflict
                 deriving (Show, Prelude.Eq)
PlutusTx.makeIsDataIndexed ''StepAction [ 
                                          ('Claim, 0), ('Commit, 1)
                                        , ('Commence, 2) --, ('Confirm, 3)
                                        , ('Delegate, 4), ('Fulfill, 5)
                                        , ('Refund, 6), ('InvokeConflictResolution, 7)
                                        , ('ResolveConflict, 8)
                                        ]
PlutusTx.unstableMakeIsData ''StepAction
PlutusTx.makeLift ''StepAction

When I make use of PlutusTx.makeIsDataIndexed:

PlutusTx.makeIsDataIndexed ''CommittedBy [ ('RequesterCommitted, 9), ('PerformerCommitted, 10) ]
PlutusTx.makeLift ''CommittedBy

The error message becomes:

Error :
      -------
      (Slot {getSlot = 6},GenericFail "GYBuildTxException (GYBuildTxBodyErrorAutoBalance (TxBodyScriptExecutionError [(ScriptWitnessIndexTxIn 1,ScriptErrorEvaluationFailed (CekError An error has occurred:\nThe machine terminated because of an error, either from a built-in function or from an explicit use of 'error'.) [\"PT1\"])]))")

It works fine when the validator directly returns True:

{-# INLINABLE mkStepValidator #-}
mkStepValidator :: StepSettings -> Step -> StepAction -> PlutusV2.ScriptContext -> Bool
mkStepValidator StepSettings{..} st@Step{..} sa ctx = True

But returns the error message if it is implemented so:

{-# INLINABLE mkStepValidator #-}
mkStepValidator :: StepSettings -> Step -> StepAction -> PlutusV2.ScriptContext -> Bool
mkStepValidator StepSettings{..} st@Step{..} sa ctx =
  let info :: PlutusV2.TxInfo
      info = PlutusV2.scriptContextTxInfo ctx

      ...
    in
      case sa of
        Commit committer    -> True
        _ -> True

[effectfully]

Thank you, we'll look into it.

[zliu41]

I don't think there's anything wrong with your redeemer definition, but the actual redeemer submitted in your transaction must match it, and it seems like it doesn't. I'd examine the code where you construct the transaction.