show trace on UnknownFailure

lib/Echidna/Etheno.hs

@@ -178,7 +178,7 @@ execEthenoTxs et = do
  (_ , AccountCreated _) -> pure ()
  (Reversion, _) -> void $ put vm
  (HandleEffect (Query q), _) -> crashWithQueryError q et
- (VMFailure x, _) -> vmExcept x >> M.fail "impossible"
+ (VMFailure x, _) -> vmExcept Nothing x >> M.fail "impossible"
  (VMSuccess (ConcreteBuf bc),
  ContractCreated _ ca _ _ _ _) -> do
  #env % #contracts % at (LitAddr ca) % _Just % #code .= InitCode mempty mempty

lib/Echidna/Exec.hs

@@ -24,9 +24,10 @@ import System.Process (readProcessWithExitCode)
 
 import EVM (bytecode, replaceCodeOfSelf, loadContract, exec1, vmOpIx)
 import EVM.ABI
+import EVM.Dapp (DappInfo)
 import EVM.Exec (exec, vmForEthrunCreation)
 import EVM.Fetch qualified
-import EVM.Format (hexText)
+import EVM.Format (hexText, showTraceTree)
 import EVM.Types hiding (Env, Gas)
 
 import Echidna.Events (emptyEvents)
@@ -70,9 +71,12 @@ pattern Illegal :: VMResult Concrete s
 pattern Illegal <- VMFailure (classifyError -> IllegalE)
 
 -- | Given an execution error, throw the appropriate exception.
-vmExcept :: MonadThrow m => EvmError -> m ()
-vmExcept e = throwM $
- case VMFailure e of {Illegal -> IllegalExec e; _ -> UnknownFailure e}
+vmExcept :: (MonadThrow m, MonadState (VM Concrete RealWorld) m) => Maybe DappInfo -> EvmError -> m ()
+vmExcept maybeDapp e = do
+ vm <- get
+ let trace = maybe "" (`showTraceTree` vm) maybeDapp
+ throwM $
+ case VMFailure e of {Illegal -> IllegalExec e; _ -> UnknownFailure e trace}
 
 execTxWith
  :: (MonadIO m, MonadState (VM Concrete RealWorld) m, MonadReader Env m, MonadThrow m)
@@ -201,7 +205,7 @@ execTxWith executeTx tx = do
  #state % #callvalue .= callvalueBeforeVMReset
  #traces .= tracesBeforeVMReset
  #state % #codeContract .= codeContractBeforeVMReset
- (VMFailure x, _) -> vmExcept x
+ (VMFailure x, _) -> asks (.dapp) >>= (\dapp -> vmExcept (Just dapp) x)
  (VMSuccess (ConcreteBuf bytecode'), SolCreate _) -> do
  -- Handle contract creation.
  #env % #contracts % at (LitAddr tx.dst) % _Just % #code .= InitCode mempty mempty

lib/Echidna/Types.hs

@@ -3,22 +3,24 @@ module Echidna.Types where
 import Control.Exception (Exception)
 import Control.Monad.State.Strict (MonadState, get, put, MonadIO(liftIO), runStateT)
 import Control.Monad.ST (RealWorld, stToIO)
+import Data.Text (Text, unpack)
 import Data.Word (Word64)
 import EVM (initialContract)
 import EVM.Types
 
 -- | We throw this when our execution fails due to something other than reversion.
-data ExecException = IllegalExec EvmError | UnknownFailure EvmError
+data ExecException = IllegalExec EvmError | UnknownFailure EvmError Text
 
 instance Show ExecException where
  show = \case
  IllegalExec e -> "VM attempted an illegal operation: " ++ show e
- UnknownFailure (MaxCodeSizeExceeded limit actual) ->
+ UnknownFailure (MaxCodeSizeExceeded limit actual) _ ->
  "Max code size exceeded. " ++ codeSizeErrorDetails limit actual
- UnknownFailure (MaxInitCodeSizeExceeded limit actual) ->
+ UnknownFailure (MaxInitCodeSizeExceeded limit actual) _ ->
  "Max init code size exceeded. " ++ codeSizeErrorDetails limit actual
- UnknownFailure e -> "VM failed for unhandled reason, " ++ show e
+ UnknownFailure e trace -> "VM failed for unhandled reason, " ++ show e
  ++ ". This shouldn't happen. Please file a ticket with this error message and steps to reproduce!"
+ ++ " Stack trace:\n" ++ unpack trace
  where
  codeSizeErrorDetails limit actual =
  "Configured limit: " ++ show limit ++ ", actual: " ++ show actual