From b1e854d660b03cc3f7f25dce44e673b9e5bcaf32 Mon Sep 17 00:00:00 2001
From: Peter Simons <simons@cryp.to>
Date: Sat, 28 Mar 2015 11:46:27 +0100
Subject: [PATCH] ghcjs: fix evaluation error in with-packages-wrapper.nix some
 more

---
 pkgs/development/haskell-modules/with-packages-wrapper.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/development/haskell-modules/with-packages-wrapper.nix b/pkgs/development/haskell-modules/with-packages-wrapper.nix
index ac887a3f60e4..be708e7da577 100644
--- a/pkgs/development/haskell-modules/with-packages-wrapper.nix
+++ b/pkgs/development/haskell-modules/with-packages-wrapper.nix
@@ -51,7 +51,7 @@ buildEnv {
   postBuild = ''
     . ${makeWrapper}/nix-support/setup-hook
 
-    ${optionalString ghc.isGhcjs ''
+    ${optionalString (ghc.isGhcjs or false) ''
     cp -r "${ghc}/${ghc.libDir}/"* ${libDir}/
     ''}