Initial attempt (gzip -n and preserve post-processed manifest timestamp)reproducible-dist

Turns our this is not enough since tar saves timestamps (as well as owner
information, file order, etc) including for directories and getting rid of
that in a portable way is not going to be easy. Looks like the most plausible
way would be to switch to embedded libarchive (provided it's possible to
achieve everything we need).

1 files changed, 18 insertions, 1 deletions

diff --git a/libbuild2/version/init.cxx b/libbuild2/version/init.cxx
index ced9c68..88f1080 100644
--- a/libbuild2/version/init.cxx
+++ b/libbuild2/version/init.cxx
@@ -374,7 +374,24 @@ namespace build2
                                      path::temp_path ("manifest"),
                                      m.version));
 
-      mvfile (t.path, f, verb_never);
+
+
+      // Copy the original timestamps in order produce the same archive for
+      // the same distribution.
+      //
+      try
+      {
+        entry_time et (file_time (f));
+
+        mvfile (t.path, f, verb_never);
+
+        file_time (f, et);
+      }
+      catch (const system_error& e)
+      {
+        fail << "unable to get/set timestamp for " << f << ": " << e;
+      }
+
       t.cancel ();
     }