From 22d665019a3770148929b7504c73bcdbe025ec12 Mon Sep 17 00:00:00 2001
From: Shea Levy <shea@shealevy.com>
Date: Thu, 5 Dec 2013 11:51:54 -0500
Subject: [PATCH] builtins.storePath: Try to substitute the path if it is not
 yet valid

Signed-off-by: Shea Levy <shea@shealevy.com>
---
 src/libexpr/primops.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 9c9d202ed..6d09bb7b1 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -582,8 +582,8 @@ static void prim_storePath(EvalState & state, Value * * args, Value & v)
     if (!isInStore(path))
         throw EvalError(format("path `%1%' is not in the Nix store") % path);
     Path path2 = toStorePath(path);
-    if (!store->isValidPath(path2))
-        throw EvalError(format("store path `%1%' is not valid") % path2);
+    if (!settings.readOnlyMode)
+        store->ensurePath(path2);
     context.insert(path2);
     mkString(v, path, context);
 }