File reproducible-from-environment.patch of Package maven-archiver

--- maven-archiver-3.6.3/pom.xml	2025-07-25 08:59:38.427807182 +0200
+++ maven-archiver-3.6.3/pom.xml	2025-07-25 08:59:51.766807935 +0200
@@ -115,4 +115,22 @@
       <scope>test</scope>
     </dependency>
   </dependencies>
+
+  <build>
+    <pluginManagement>
+      <plugins>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-surefire-plugin</artifactId>
+          <configuration>
+            <redirectTestOutputToFile>true</redirectTestOutputToFile>
+            <excludedEnvironmentVariables>
+              <excludedEnvironmentVariable>SOURCE_DATE_EPOCH</excludedEnvironmentVariable>
+            </excludedEnvironmentVariables>
+          </configuration>
+        </plugin>
+      </plugins>
+    </pluginManagement>
+  </build>
+
 </project>
--- maven-archiver-3.6.3/src/main/java/org/apache/maven/archiver/MavenArchiver.java	2025-07-25 08:59:38.426221268 +0200
+++ maven-archiver-3.6.3/src/main/java/org/apache/maven/archiver/MavenArchiver.java	2025-07-25 09:00:55.991543025 +0200
@@ -66,7 +66,6 @@
  *
  * @author <a href="evenisse@apache.org">Emmanuel Venisse</a>
  * @author kama
- * @version $Id: $Id
  */
 public class MavenArchiver {
 
@@ -745,6 +744,9 @@
      * <p>Either as {@link java.time.format.DateTimeFormatter#ISO_OFFSET_DATE_TIME} or as a number representing seconds
      * since the epoch (like <a href="https://reproducible-builds.org/docs/source-date-epoch/">SOURCE_DATE_EPOCH</a>).
      *
+     * <p>Since 3.6.4, if not configured or disabled, the {@code SOURCE_DATE_EPOCH} environment variable is used as
+     * a fallback value, to ease forcing Reproducible Build externally when the build has not enabled it natively in POM.
+     *
      * @param outputTimestamp the value of {@code ${project.build.outputTimestamp}} (may be {@code null})
      * @return the parsed timestamp as an {@code Optional<Instant>}, {@code empty} if input is {@code null} or input
      *         contains only 1 character (not a number)
@@ -753,12 +755,19 @@
      *             the valid range 1980-01-01T00:00:02Z to 2099-12-31T23:59:59Z as defined by
      *             <a href="https://pkwaredownloads.blob.core.windows.net/pem/APPNOTE.txt">ZIP application note</a>,
      *             section 4.4.6.
+     * @see <a href="https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=74682318">Maven Wiki "Reproducible/Verifiable
+     *      Builds"</a>
      */
     public static Optional<Instant> parseBuildOutputTimestamp(String outputTimestamp) {
-        // Fail-fast on nulls
+        // Fail fast on null and no timestamp configured (1 character configuration is useful to override
+        // a full value during pom inheritance)
+        if (outputTimestamp == null || (outputTimestamp.length() < 2 && !isNumeric(outputTimestamp))) {
+            // Reproducible Builds not configured or disabled => fallback to SOURCE_DATE_EPOCH env
+            outputTimestamp = System.getenv("SOURCE_DATE_EPOCH");
         if (outputTimestamp == null) {
             return Optional.empty();
         }
+        }
 
         // Number representing seconds since the epoch
         if (isNumeric(outputTimestamp)) {
@@ -771,12 +780,6 @@
             return Optional.of(date);
         }
 
-        // no timestamp configured (1 character configuration is useful to override a full value during pom
-        // inheritance)
-        if (outputTimestamp.length() < 2) {
-            return Optional.empty();
-        }
-
         try {
             // Parse the date in UTC such as '2011-12-03T10:15:30Z' or with an offset '2019-10-05T20:37:42+06:00'.
             final Instant date = OffsetDateTime.parse(outputTimestamp)