Old backups aren't deleted

[php-coder]

Local and Remote metadata are synchronized, no sync needed.
Last full backup date: Tue Oct 29 00:50:02 2019
--------------[ Backup Statistics ]--------------
StartTime 1574200280.64 (Wed Nov 20 00:51:20 2019)
EndTime 1574200280.96 (Wed Nov 20 00:51:20 2019)
ElapsedTime 0.32 (0.32 seconds)
SourceFiles 782
SourceFileSize 171955413 (164 MB)
NewFiles 2
NewFileSize 394560 (385 KB)
DeletedFiles 0
ChangedFiles 0
ChangedFileSize 0 (0 bytes)
ChangedDeltaSize 0 (0 bytes)
DeltaEntries 2
RawDeltaSize 324928 (317 KB)
TotalDestinationSizeChange 324885 (317 KB)
Errors 0
-------------------------------------------------

Synchronizing remote metadata to local cache...
Copying duplicity-inc.20191118T215001Z.to.20191119T215001Z.manifest.gpg to local cache.
Copying duplicity-new-signatures.20191118T215001Z.to.20191119T215001Z.sigtar.gpg to local cache.
Last full backup date: Tue Oct 29 00:50:02 2019
There are backup set(s) at time(s):
Wed Nov 15 02:04:28 2017
Wed Nov 15 02:05:45 2017
Sun Nov 19 22:58:16 2017
Sun Nov 19 23:20:01 2017
Mon Nov 20 00:50:01 2017
......
Tue May 21 00:50:02 2019
Wed May 22 00:50:01 2019
Thu May 23 00:50:01 2019
Fri May 24 00:50:02 2019
Which can't be deleted because newer sets depend on them.
No old backup sets found, nothing deleted.

[php-coder]

It seems like this is the issue: https://lists.gnu.org/archive/html/duplicity-talk/2017-03/msg00017.html

[php-coder]

$  duplicity collection-status --name=uploads <skip>
Local and Remote metadata are synchronized, no sync needed.
Last full backup date: Wed Oct 30 00:45:01 2019
Collection Status
-----------------
Connecting with backend: BackendWrapper
Archive dir: /data/mystamps/.cache/duplicity/uploads

Found 6 secondary backup chains.
Secondary chain 1 of 6:
-------------------------
Chain start time: Sat Nov 11 19:07:32 2017
Chain end time: Mon May 27 00:45:01 2019
Number of contained backup sets: 555
Total number of contained volumes: 555
 Type of backup set:                            Time:      Num volumes:
                Full         Sat Nov 11 19:07:32 2017                 1
         Incremental         Wed Nov 15 01:57:21 2017                 1
         Incremental         Sun Nov 19 20:38:01 2017                 1
         Incremental         Sun Nov 19 21:38:01 2017                 1
         Incremental         Sun Nov 19 22:38:01 2017                 1
...
         Incremental         Sat May 25 00:45:02 2019                 1
         Incremental         Sun May 26 00:45:01 2019                 1
         Incremental         Mon May 27 00:45:01 2019                 1
-------------------------
...

[php-coder]

I've executed duplicity remove-all-but-n-full 5 --force --name=uploads in order to cleanup old backups.

[php-coder]

And duplicity remove-all-but-n-full 5 --force --name=mysql-backups as well.