From 7fc1f82d2ad9d511bb7d200bf5ad60ff814aea44 Mon Sep 17 00:00:00 2001
From: Joshua Simmons <joshua.simmons@emptypath.com>
Date: Mon, 21 Dec 2015 21:25:57 -0700
Subject: [PATCH] give an error when a template doesn't include a .cabal file

fixes #1535
---
 src/Stack/New.hs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/Stack/New.hs b/src/Stack/New.hs
index 71c7f346fc..41ece17176 100644
--- a/src/Stack/New.hs
+++ b/src/Stack/New.hs
@@ -197,6 +197,10 @@ applyTemplate project template nonceParams dir templateText = do
                    throwM (InvalidTemplate template (show e)))
     when (M.null files) $
          throwM (InvalidTemplate template "Template did not specify any files.")
+    unless (any (".cabal" `isSuffixOf`) . M.keys $ files) $
+         throwM (InvalidTemplate template "Template does not contain a .cabal\
+                                          \ file, and the result could not be\
+                                          \ made into a stack project.")
     liftM
         M.fromList
         (mapM