From 9c8a2a0b296ea4d604200630498604d4386287da Mon Sep 17 00:00:00 2001
From: Paul Schaub <vanitasvitae@fsfe.org>
Date: Thu, 24 Jun 2021 18:58:24 +0200
Subject: [PATCH] Make builds reproducible

---
 build.gradle | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/build.gradle b/build.gradle
index 32475846..63503b1f 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,5 +1,3 @@
-import java.text.SimpleDateFormat
-
 buildscript {
 
     repositories {
@@ -55,11 +53,16 @@ allprojects {
         mavenCentral()
     }
 
+    // Reproducible Builds
+    tasks.withType(AbstractArchiveTask) {
+        preserveFileTimestamps = false
+        reproducibleFileOrder = true
+    }
+
     project.ext {
         junitVersion = '5.7.1'
         rootConfigDir = new File(rootDir, 'config')
         gitCommit = getGitCommit()
-        builtDate = (new SimpleDateFormat("yyyy-MM-dd")).format(new Date())
         isContinuousIntegrationEnvironment = Boolean.parseBoolean(System.getenv('CI'))
         isReleaseVersion = !isSnapshot
         signingRequired = !(isSnapshot || isContinuousIntegrationEnvironment)
@@ -188,9 +191,10 @@ subprojects {
         doLast {
             def propertiesFile = file "$generatedVersionDir/version.properties"
             propertiesFile.parentFile.mkdirs()
-            def properties = new Properties()
-            properties.setProperty("version", rootProject.version.toString())
-            propertiesFile.withWriter { properties.store(it, null) }
+            propertiesFile.createNewFile()
+            // Instead of using a Properties object here, we directly write to the file
+            //  since Properties adds a timestamp, ruining reproducibility
+            propertiesFile.write("version="+rootProject.version.toString())
         }
     }
     processResources.dependsOn generateVersionProperties