When -v is specified with prune, also show the timestamp of each

archive, which is helpful for debugging.  Unify this with the
formatting done by "attic list".  The spacing is chosen so that
the attic prune output is 79 characters wide when the archive
names are at most 36 characters.

attic/archiver.py

@@ -14,7 +14,7 @@ from attic.key import key_creator
 from attic.helpers import Error, location_validator, format_time, \
     format_file_mode, ExcludePattern, exclude_path, adjust_patterns, to_localtime, \
     get_cache_dir, get_keys_dir, format_timedelta, prune_within, prune_split, \
-    Manifest, remove_surrogates, update_excludes
+    Manifest, remove_surrogates, update_excludes, format_archive
 from attic.remote import RepositoryServer, RemoteRepository
 
 
@@ -277,7 +277,7 @@ Type "Yes I am sure" if you understand this and want to continue.\n""")
                                                   remove_surrogates(item[b'path']), extra))
         else:
             for archive in sorted(Archive.list_archives(repository, key, manifest), key=attrgetter('ts')):
-                print('%-20s %s' % (archive.metadata[b'name'], to_localtime(archive.ts).strftime('%c')))
+                print(format_archive(archive))
         return self.exit_code
 
     def do_info(self, args):
@@ -329,12 +329,12 @@ Type "Yes I am sure" if you understand this and want to continue.\n""")
         to_delete = [a for a in archives if a not in keep]
 
         for archive in keep:
-            self.print_verbose('Keeping archive "%s"' % archive.name)
+            self.print_verbose('Keeping archive: %s' % format_archive(archive))
         for archive in to_delete:
             if args.dry_run:
-                self.print_verbose('Would prune     "%s"' % archive.name)
+                self.print_verbose('Would prune:     %s' % format_archive(archive))
             else:
-                self.print_verbose('Pruning archive "%s"' % archive.name)
+                self.print_verbose('Pruning archive: %s' % format_archive(archive))
                 archive.delete(cache)
         return self.exit_code
 

attic/helpers.py

@@ -288,6 +288,10 @@ def format_file_size(v):
         return '%d B' % v
 
 
+def format_archive(archive):
+    return '%-36s %s' % (archive.name, to_localtime(archive.ts).strftime('%c'))
+
+
 class IntegrityError(Error):
     """Data integrity error"""