guix/gnu/packages/patches/mono-mdoc-timestamping.patch

--- mono-4.4.1/mcs/class/monodoc/Monodoc/storage/ZipStorage.cs.orig	2018-11-26 22:16:25.008879747 +0100
+++ mono-4.4.1/mcs/class/monodoc/Monodoc/storage/ZipStorage.cs	2018-11-26 22:21:53.969770985 +0100
@@ -74,6 +74,12 @@
 				id = GetNewCode ();
 
 			ZipEntry entry = new ZipEntry (id);
+			var SOURCE_DATE_EPOCH_string = Environment.GetEnvironmentVariable("SOURCE_DATE_EPOCH");
+			if (SOURCE_DATE_EPOCH_string != null)
+			{
+				var SOURCE_DATE_EPOCH = Convert.ToInt64(SOURCE_DATE_EPOCH_string);
+				entry.DateTime = new DateTime(SOURCE_DATE_EPOCH, DateTimeKind.Utc);
+			}
 			zipOutput.PutNextEntry (entry);
 		}