From 74ab0695b5bec5c7239744a89df5b2a7112e916b Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <e.dolstra@tudelft.nl>
Date: Thu, 17 Feb 2005 15:48:50 +0000
Subject: [PATCH] * Compatibility hack with older user environments.

---
 src/nix-env/main.cc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/nix-env/main.cc b/src/nix-env/main.cc
index 6e4ba61e5..71c22d1a5 100644
--- a/src/nix-env/main.cc
+++ b/src/nix-env/main.cc
@@ -197,7 +197,9 @@ static void createUserEnv(EvalState & state, const UserEnvElems & elems,
     PathSet drvsToBuild;
     for (UserEnvElems::const_iterator i = elems.begin(); 
          i != elems.end(); ++i)
-        if (i->second.drvPath != "")
+        /* Call to `isDerivation' is for compatibility with Nix <= 0.7
+           user environments. */
+        if (i->second.drvPath != "" && isDerivation(i->second.drvPath))
             drvsToBuild.insert(i->second.drvPath);
 
     debug(format("building user environment dependencies"));