From 125e7ea1305a5668ab704e8c10b8c3d4a2ed40ac Mon Sep 17 00:00:00 2001
From: Michael Snoyman <michael@snoyman.com>
Date: Fri, 26 Dec 2014 10:16:11 +0200
Subject: [PATCH] removeTreeIfExists

---
 Handler/Haddock.hs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Handler/Haddock.hs b/Handler/Haddock.hs
index e4c4767..ab6b94d 100644
--- a/Handler/Haddock.hs
+++ b/Handler/Haddock.hs
@@ -267,6 +267,8 @@ createHaddockUnpacker root store runDB' = do
   where
     dirs = mkDirs root
 
+    removeTreeIfExists fp = whenM (isDirectory fp) (removeTree fp)
+
     doDirsExist ident = do
         e1 <- isDirectory $ dirGzIdent dirs ident
         if e1
@@ -276,8 +278,8 @@ createHaddockUnpacker root store runDB' = do
         toRun <-
             if forceUnpack
                 then do
-                    removeTree $ dirRawIdent dirs ident
-                    removeTree $ dirGzIdent dirs ident
+                    removeTreeIfExists $ dirRawIdent dirs ident
+                    removeTreeIfExists $ dirGzIdent dirs ident
                     return True
                 else not <$> doDirsExist ident
         when toRun $ do