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diff --git a/src/Text/Pandoc/Lua/Marshaling/PandocError.hs b/src/Text/Pandoc/Lua/Marshaling/PandocError.hs
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+++ b/src/Text/Pandoc/Lua/Marshaling/PandocError.hs
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+{-# OPTIONS_GHC -fno-warn-orphans #-}
+{-# LANGUAGE LambdaCase           #-}
+{-# LANGUAGE OverloadedStrings    #-}
+{-# LANGUAGE ScopedTypeVariables  #-}
+{- |
+   Module      : Text.Pandoc.Lua.Marshaling.PandocError
+   Copyright   : © 2020 Albert Krewinkel
+   License     : GNU GPL, version 2 or above
+
+   Maintainer  : Albert Krewinkel <tarleb+pandoc@moltkeplatz.de>
+   Stability   : alpha
+
+Marshaling of @'PandocError'@ values.
+-}
+module Text.Pandoc.Lua.Marshaling.PandocError
+  ( peekPandocError
+  , pushPandocError
+  )
+  where
+
+import Foreign.Lua (Lua, Peekable, Pushable, StackIndex)
+import Text.Pandoc.Error (PandocError (PandocLuaError))
+
+import qualified Foreign.Lua as Lua
+import qualified Foreign.Lua.Userdata as Lua
+import qualified Text.Pandoc.Lua.Util as LuaUtil
+import qualified Text.Pandoc.UTF8 as UTF8
+
+-- | Userdata name used by Lua for the @PandocError@ type.
+pandocErrorName :: String
+pandocErrorName = "pandoc error"
+
+-- | Peek a @'PandocError'@ element to the Lua stack.
+pushPandocError :: PandocError -> Lua ()
+pushPandocError = Lua.pushAnyWithMetatable pushPandocErrorMT
+  where
+    pushPandocErrorMT = Lua.ensureUserdataMetatable pandocErrorName $
+      LuaUtil.addFunction "__tostring" __tostring
+
+-- | Retrieve a @'PandocError'@ from the Lua stack.
+peekPandocError :: StackIndex -> Lua PandocError
+peekPandocError idx = Lua.ltype idx >>= \case
+  Lua.TypeUserdata -> do
+    errMb <- Lua.toAnyWithName idx pandocErrorName
+    return $ case errMb of
+      Just err -> err
+      Nothing  -> PandocLuaError "could not retrieve original error"
+  _ -> do
+    Lua.pushvalue idx
+    msg <- Lua.state >>= \l -> Lua.liftIO (Lua.errorMessage l)
+    return $ PandocLuaError (UTF8.toText msg)
+
+-- | Convert to string.
+__tostring :: PandocError -> Lua String
+__tostring = return . show
+
+--
+-- Instances
+--
+
+instance Pushable PandocError where
+  push = pushPandocError
+
+instance Peekable PandocError where
+  peek = peekPandocError