improved error reporting

1 files changed, 2 insertions, 2 deletions

diff --git a/fsmgr.hs b/fsmgr.hs
index c290a74..3a59a53 100644
--- a/fsmgr.hs
+++ b/fsmgr.hs
@@ -296,8 +296,8 @@ shakeRules = do
   "_build/*.btrfs" %> \out -> do
     let cfgFile = (out -<.> "yaml.canon")
     need [cfgFile]
-    cfg <- read <$> readFile' cfgFile
-    buildRoot cfg out
+    cfg <- readEither <$> readFile' cfgFile
+    either (error . (("Error parsing file: " ++ cfgFile ++ ": ") ++)) (flip buildRoot out) cfg
   "*.btrfs" %> \out -> do
     need ["_build" </> out]
     -- WithStderr False needed for `cp` to interact with the tty