Use traceFile (bad)

.hlint.yaml

@@ -1,6 +1,6 @@
 ---
 - functions:
-  - {name: unsafePerformIO, within: [PlutusPrelude, Language.PlutusCore.Generators.Internal.Entity, Language.PlutusCore.Constant.Dynamic.Call, Language.PlutusCore.Constant.Dynamic.Emit, Language.PlutusCore.Constant.Dynamic.Instances, Language.PlutusCore.StdLib.Type, Language.PlutusTx.Plugin, Language.PlutusTx.Evaluation]}
+  - {name: unsafePerformIO, within: [PlutusPrelude, Language.PlutusCore.Generators.Internal.Entity, Language.PlutusCore.Constant.Dynamic.Call, Language.PlutusCore.Constant.Dynamic.Emit, Language.PlutusCore.Constant.Dynamic.Instances, Language.PlutusCore.StdLib.Type, Language.PlutusTx.Plugin, Language.PlutusTx.Evaluation, Debug.Trace.Ext]}
   - {name: error, within: [Main, PlutusPrelude, Language.PlutusCore.StdLib.Meta, Evaluation.Constant.Success, Language.PlutusCore.Constant.Apply, Language.PlutusCore.Evaluation.CkMachine, Language.PlutusCore.TypeSynthesis, Language.PlutusCore.Generators.Internal.Dependent, Language.PlutusCore.Generators.Internal.Entity, Language.PlutusCore.Generators.Internal.Utils, Language.PlutusCore.Constant.Make, DynamicBuiltins.Definition, Language.PlutusCore.TH, Language.PlutusTx.Utils, Language.PlutusIR.Compiler.Datatype, LedgerBytes]}
   - {name: undefined, within: [Language.PlutusCore.Constant.Apply, Language.PlutusTx.Lift.Class, Language.PlutusTx.Lift.Instances]}
   - {name: fromJust, within: [Language.PlutusTx.Lift]}

wallet-api/src/Debug/Trace/Ext.hs

@@ -0,0 +1,7 @@
+module Debug.Trace.Ext ( traceFile ) where
+
+import           Data.Functor     (($>))
+import           System.IO.Unsafe (unsafePerformIO)
+
+traceFile :: FilePath -> String -> a -> a
+traceFile fp contents x = unsafePerformIO $ writeFile fp contents $> x

wallet-api/src/Ledger/Scripts.hs

@@ -48,6 +48,7 @@ import           Language.PlutusTx.Lift                   (unsafeLiftProgram)
 import           Language.PlutusTx.Lift.Class             (Lift)
 import           Language.PlutusTx                        (CompiledCode, compile, getPlc)
 import           PlutusPrelude
+import Debug.Trace.Ext
 
 -- | A script on the chain. This is an opaque type as far as the chain is concerned.
 newtype Script = Script { unScript :: PLC.Program PLC.TyName PLC.Name () }
@@ -100,7 +101,7 @@ applyScript (unScript -> s1) (unScript -> s2) = Script $ s1 `PLC.applyProgram` s
 evaluateScript :: Script -> ([String], Bool)
 evaluateScript (unScript -> s) =
     case check s of
-        (Left e) -> ([logTypeErr e], False)
+        (Left e) -> traceFile "invalid.plc" (PLC.prettyPlcDefString s) ([logTypeErr e], False)
         Right{} -> (isJust . reoption) <$> evaluateCekTrace s
 
     where check = PLC.runQuoteT . PLC.typecheckPipeline PLC.defOnChainConfig

wallet-api/wallet-api.cabal

@@ -72,6 +72,8 @@ library
         Ledger.Value
         Ledger.Value.TH
         LedgerBytes
+    other-modules:
+        Debug.Trace.Ext
     hs-source-dirs: src
     default-language: Haskell2010
     build-depends: