From 44d642116087d9f22e01b457f076cc3c3a739a9d Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Mon, 3 Feb 2020 14:06:53 +0100
Subject: [PATCH] Emit narHash attribute

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

diff --git a/src/libexpr/flake/flake.cc b/src/libexpr/flake/flake.cc
index 5018b460b..a0f41e6b9 100644
--- a/src/libexpr/flake/flake.cc
+++ b/src/libexpr/flake/flake.cc
@@ -616,6 +616,10 @@ static void emitSourceInfoAttrs(
     auto pathS = state.store->printStorePath(sourceInfo.storePath);
     mkString(*state.allocAttr(vAttrs, state.sOutPath), pathS, {pathS});
 
+    assert(sourceInfo.info.narHash);
+    mkString(*state.allocAttr(vAttrs, state.symbols.create("narHash")),
+        sourceInfo.info.narHash.to_string(SRI));
+
     if (auto rev = flakeRef.input->getRev()) {
         mkString(*state.allocAttr(vAttrs, state.symbols.create("rev")),
             rev->gitRev());