From ab47868639750010db01d7e846c9203bd7f00b2d Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Thu, 2 Apr 2020 18:39:41 +0200
Subject: [PATCH] Change lastModified to the number of seconds in the epoch

'lastModifiedDate' is now a string representing the equivalent
date/time.
---
 flake.nix                        | 2 +-
 src/libexpr/primops/fetchTree.cc | 6 ++++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/flake.nix b/flake.nix
index f0e669f63..d954bd29d 100644
--- a/flake.nix
+++ b/flake.nix
@@ -13,7 +13,7 @@
       versionSuffix =
         if officialRelease
         then ""
-        else "pre${builtins.substring 0 8 self.lastModified}_${self.shortRev or "dirty"}";
+        else "pre${builtins.substring 0 8 self.lastModifiedDate}_${self.shortRev or "dirty"}";
 
       officialRelease = false;
 
diff --git a/src/libexpr/primops/fetchTree.cc b/src/libexpr/primops/fetchTree.cc
index 79ddc45f5..8a4970726 100644
--- a/src/libexpr/primops/fetchTree.cc
+++ b/src/libexpr/primops/fetchTree.cc
@@ -34,9 +34,11 @@ void emitTreeAttrs(
     if (tree.info.revCount)
         mkInt(*state.allocAttr(v, state.symbols.create("revCount")), *tree.info.revCount);
 
-    if (tree.info.lastModified)
-        mkString(*state.allocAttr(v, state.symbols.create("lastModified")),
+    if (tree.info.lastModified) {
+        mkInt(*state.allocAttr(v, state.symbols.create("lastModified")), *tree.info.lastModified);
+        mkString(*state.allocAttr(v, state.symbols.create("lastModifiedDate")),
             fmt("%s", std::put_time(std::gmtime(&*tree.info.lastModified), "%Y%m%d%H%M%S")));
+    }
 
     v.attrs->sort();
 }