PersistMarshalError reading from sqlite

I'm trying to read from an existing SQLite database using persistent-sql.

I'm getting a PersistMarshalError, and I suspect it might be a bug in the sqlite driver interpreting the sqlite output ... but would love to be wrong :)

This is the schema:

  CREATE TABLE "System" (
  'SystemId'  INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
  'SystemName'  TEXT(255) COLLATE NOCASE,
  'SystemX'  Double,
  'SystemY'  Double,
  'SystemZ'  Double,
  'SystemSize'  Double
  );

And this is the haskell test code:

{-# LANGUAGE QuasiQuotes, TypeFamilies, GeneralizedNewtypeDeriving, TemplateHaskell,
         OverloadedStrings, GADTs, FlexibleContexts, ScopedTypeVariables #-} 
import Database.Persist
import Database.Persist.Sqlite
import Database.Persist.TH
import Control.Monad.IO.Class (liftIO)
import Data.Time (UTCTime)
import Data.Text (Text)
import Control.Monad.Logger
import Control.Monad.Trans.Resource (runResourceT)

share [mkPersist sqlSettings, mkMigrate "migrateAll"] [persistUpperCase|
System
   Id Int sqltype=int sql=SystemId
   name Text Maybe sqltype=text sql=SystemName
   x Double Maybe sqltype=double sql=SystemX 
   y Double Maybe sqltype=double sql=SystemY 
   z Double Maybe sqltype=double sql=SystemZ
   size Double Maybe sqltype=double sql=SystemSize
   deriving Show
|]

connStr = "PATH_TO_DB"

main :: IO ()
main = runStdoutLoggingT $ withSqlitePool connStr 10 $ \pool ->
     runResourceT $ flip runSqlPool pool $ do
        printMigration migrateAll
        res  :: [Entity System] <- selectList [] [LimitTo 1] 
        liftIO $ print res

This is the error:

[Debug#SQL] SELECT "SystemId", "SystemName", "SystemX", "SystemY", "SystemZ", "SystemSize" FROM "System"; [] @(<unknown>
:<unknown> <unknown>:0:0)
edbpc: PersistMarshalError "field x: Expected Double, received: PersistText \"X\""

There is no row in the DB with "X" in the SystemX column.

sqlite> select * from system where systemx like '%X%';
sqlite> select * from system where systemx like '%x%';
sqlite>

What I think is happening is that the field name is being included in the sqlite output rows, and that is being parsed.

I think this because when I add 'OffsetBy 1' to the query, the error goes away and I see the actual first row from the table.