Reproducible builds: use a fixed mtime for all entries in the source tarball (#2823)

snazy · web-flow · commit 0fdaa5a54591 · 2025-10-16T17:43:26.000+02:00
This change makes generated source-tarballs binary-comparable, so that locally built one (via `./gradlew sourceTarball`) should be exactly the same as a staged one.
diff --git a/build-logic/src/main/kotlin/publishing/rootProject.kt b/build-logic/src/main/kotlin/publishing/rootProject.kt
@@ -55,6 +55,8 @@ internal fun configureOnRootProject(project: Project) =
         "archive",
         "--prefix=${e.baseName.get()}/",
         "--format=tar.gz",
+        // use a fixed mtime for reproducible tarballs, using the same timestamp as jars do
+        "--mtime=1980-02-01 00:00:00",
         "--output=${e.sourceTarball.get().asFile.relativeTo(projectDir)}",
         "HEAD",
       )

Original file line number	Diff line number	Diff line change
`@@ -55,6 +55,8 @@ internal fun configureOnRootProject(project: Project) =`
`55`	`55`	`"archive",`
`56`	`56`	`"--prefix=${e.baseName.get()}/",`
`57`	`57`	`"--format=tar.gz",`
	`58`	`+ // use a fixed mtime for reproducible tarballs, using the same timestamp as jars do`
	`59`	`+ "--mtime=1980-02-01 00:00:00",`
`58`	`60`	`"--output=${e.sourceTarball.get().asFile.relativeTo(projectDir)}",`
`59`	`61`	`"HEAD",`
`60`	`62`	`)`