File reproducible-timestamp.patch of Package sbt.34548

--- sbt-0.13.18/ivy/src/main/scala/sbt/ProjectResolver.scala	2023-09-14 19:14:50.159288785 +0200
+++ sbt-0.13.18/ivy/src/main/scala/sbt/ProjectResolver.scala	2023-09-17 16:10:27.587598975 +0200
@@ -38,7 +38,9 @@
 
   def report(revisionId: ModuleRevisionId): MetadataArtifactDownloadReport =
     {
-      val artifact = DefaultArtifact.newIvyArtifact(revisionId, new Date)
+      val sde = System.getenv("SOURCE_DATE_EPOCH")
+      val now = if (sde != null) (new Date(1000 * sde.toLong)) else (new Date)
+      val artifact = DefaultArtifact.newIvyArtifact(revisionId, now)
       val r = new MetadataArtifactDownloadReport(artifact)
       r.setSearched(false)
       r.setDownloadStatus(DownloadStatus.FAILED)
--- sbt-0.13.18/project/Util.scala	2023-09-14 19:14:50.189288995 +0200
+++ sbt-0.13.18/project/Util.scala	2023-09-17 16:10:13.460829055 +0200
@@ -62,7 +62,9 @@
       import java.util.{ Date, TimeZone }
       val formatter = new java.text.SimpleDateFormat("yyyyMMdd'T'HHmmss")
       formatter.setTimeZone(TimeZone.getTimeZone("GMT"))
-      val timestamp = formatter.format(new Date)
+      val sde = System.getenv("SOURCE_DATE_EPOCH")
+      val now = if (sde != null) (new Date(1000 * sde.toLong)) else (new Date)
+      val timestamp = formatter.format(now)
       val content = versionLine(version) + "\ntimestamp=" + timestamp
       val f = dir / "xsbt.version.properties"
       if (!f.exists || f.lastModified < lastCompilationTime(analysis) || !containsVersion(f, version)) {