From 0b90a7f67f4df722a5c29773fcf8376d631f1fc8 Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Tue, 5 Nov 2019 19:45:48 -0500
Subject: [PATCH] lispPackages.clwrapper: NIX_LISP_LD_LIBRARY_PATH might be
 undefined

---
 pkgs/development/lisp-modules/clwrapper/setup-hook.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/development/lisp-modules/clwrapper/setup-hook.sh b/pkgs/development/lisp-modules/clwrapper/setup-hook.sh
index 8975ada5320..da2303a18bf 100644
--- a/pkgs/development/lisp-modules/clwrapper/setup-hook.sh
+++ b/pkgs/development/lisp-modules/clwrapper/setup-hook.sh
@@ -27,7 +27,7 @@ setLisp () {
 
 collectNixLispLDLP () {
      if echo "$1/lib"/lib*.so* | grep . > /dev/null; then
-	 export NIX_LISP_LD_LIBRARY_PATH="$NIX_LISP_LD_LIBRARY_PATH${NIX_LISP_LD_LIBRARY_PATH:+:}$1/lib"
+	 export NIX_LISP_LD_LIBRARY_PATH="${NIX_LISP_LD_LIBRARY_PATH-}${NIX_LISP_LD_LIBRARY_PATH:+:}$1/lib"
      fi
 }