From 18047d4625b46ae001abc649096ab9ecd4c54560 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <e.dolstra@tudelft.nl>
Date: Thu, 19 Jan 2012 23:07:42 +0000
Subject: [PATCH] * Add some debug output to print the derivation name once
 it's known.   This makes it easier to pinpoint the source of a crash.

---
 src/libexpr/primops.cc | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 21c9fb351..01f933da1 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -305,7 +305,10 @@ static void prim_derivationStrict(EvalState & state, Value * * args, Value & v)
                 drv.env[key] = s;
                 if (key == "builder") drv.builder = s;
                 else if (i->name == state.sSystem) drv.platform = s;
-                else if (i->name == state.sName) drvName = s;
+                else if (i->name == state.sName) {
+                    drvName = s;
+                    printMsg(lvlVomit, format("derivation name is `%1%'") % drvName);
+                }
                 else if (key == "outputHash") outputHash = s;
                 else if (key == "outputHashAlgo") outputHashAlgo = s;
                 else if (key == "outputHashMode") {