diff --git a/stack.yaml b/stack.yaml
index dc15043..1b59034 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -2,6 +2,7 @@
 
 # Specifies the GHC version and set of packages available (e.g., lts-3.5, nightly-2015-09-21, ghc-7.10.2)
 resolver: lts-9.0
+#resolver: nightly-2017-07-31
 
 # Local packages, usually specified by relative directory name
 packages:
diff --git a/tools/Language/SQL/SimpleSQL/ErrorMessages.lhs b/tools/Language/SQL/SimpleSQL/ErrorMessages.lhs
index 5345373..b8567ab 100644
--- a/tools/Language/SQL/SimpleSQL/ErrorMessages.lhs
+++ b/tools/Language/SQL/SimpleSQL/ErrorMessages.lhs
@@ -55,7 +55,7 @@ expression parts.
 
 > module Language.SQL.SimpleSQL.ErrorMessages where
 
-> import Language.SQL.SimpleSQL.Parser
+> {-import Language.SQL.SimpleSQL.Parser
 > import Data.List
 > import Text.Groom
 
@@ -147,3 +147,4 @@ window functions
 > pExprs x y =
 >     let l = valExprs x ++ queryExprs y
 >     in intercalate "\n\n\n\n" $ map (\(a,b) -> a ++ "\n" ++ b) l
+> -}