Don't fail when cabal sandbox pkgdb doesn't exist

2 files changed, 9 insertions, 1 deletions

diff --git a/CabalHelper/Compile.hs b/CabalHelper/Compile.hs
index 54771b1..59bb48c 100644
--- a/CabalHelper/Compile.hs
+++ b/CabalHelper/Compile.hs
@@ -97,7 +97,8 @@ compileHelper opts cabalVer projdir distdir = withHelperSources $ \chdir -> do
    compileSandbox :: FilePath -> MaybeT IO (Either ExitCode FilePath)
    compileSandbox chdir = do
        sandbox <- MaybeT $ getSandboxPkgDb projdir (display buildPlatform) =<< ghcVersion opts
-       ver <- MaybeT $ find (== cabalVer) <$> listCabalVersions' opts (Just sandbox)
+       ver <- MaybeT $ logSomeError opts "compileSandbox" $
+         find (== cabalVer) <$> listCabalVersions' opts (Just sandbox)
        vLog opts $ logMsg ++ "sandbox package-db"
        liftIO $ compileWithPkg chdir (Just sandbox) ver
 
diff --git a/CabalHelper/Log.hs b/CabalHelper/Log.hs
index 9e04df0..bbc84a6 100644
--- a/CabalHelper/Log.hs
+++ b/CabalHelper/Log.hs
@@ -2,6 +2,7 @@ module CabalHelper.Log where
 
 import Control.Monad
 import Control.Monad.IO.Class
+import Control.Exception as E
 import Data.String
 import System.IO
 import Prelude
@@ -12,3 +13,9 @@ vLog :: MonadIO m => Options -> String -> m ()
 vLog Options { verbose = True } msg =
     liftIO $ hPutStrLn stderr msg
 vLog _ _ = return ()
+
+logSomeError :: Options -> String -> IO (Maybe a) -> IO (Maybe a)
+logSomeError opts label a = do
+  a `E.catch` \se@(SomeException _) -> do
+      vLog opts $ label ++ ": " ++ show se
+      return Nothing