1 files changed, 18 insertions, 0 deletions
diff --git a/src/Propellor/Exception.hs b/src/Propellor/Exception.hs
new file mode 100644
index 00000000..f6fd15f1
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+++ b/src/Propellor/Exception.hs
@@ -0,0 +1,18 @@
+{-# LANGUAGE PackageImports #-}
+
+module Propellor.Exception where
+
+import qualified "MonadCatchIO-transformers" Control.Monad.CatchIO as M
+import Control.Exception
+
+import Propellor.Types
+import Propellor.Message
+
+-- | Catches IO exceptions and returns FailedChange.
+catchPropellor :: Propellor Result -> Propellor Result
+catchPropellor a = either err return =<< tryPropellor a
+  where
+	err e =  warningMessage (show e) >> return FailedChange
+
+tryPropellor :: Propellor a -> Propellor (Either IOException a)
+tryPropellor = M.try