preflight :: FilePath -> Sh [T.Text]
preflight script = liftM catMaybes checks
    where checks = sequence [
            test_px psql_path >>= (\e -> return $ if e then Nothing else Just $ "psql not found in $PATH.")
           ,test_f script >>= (\e -> return $ if e then Nothing else Just $ (toTextIgnore script) `T.append` " not found.")
           ]
preflight :: FilePath -> Sh [T.Text]
preflight script = liftM catMaybes checks
    where checks = sequence [
            test_px psql_path >>= (\e -> return $ if e then Nothing else Just $ "psql not found in $PATH.")
           ,test_f script >>= (\e -> return $ if e then Nothing else Just $ (toTextIgnore script) `T.append` " not found.")
           ]
preflight script = liftM catMaybes checks
    where checks = sequence [
            test_px psql_path >>= (\e -> return $ if e then Nothing else Just $ "psql not found in $PATH.")
           ,test_f script >>= (\e -> return $ if e then Nothing else Just $ (toTextIgnore script) `T.append` " not found.")
           ]