Try upping your ulimit on num files from 1024 to 8192 or higher.

To do this for duplicity, run like so:
$ ulimit -n 8192
$ duplicity ...

To set this system wide see:
https://www.google.com/search?q=linux+increase+number+of+open+files&oq=linux+increase+num&aqs=chrome.0.0j69i57j0l4.12567j0j7&sourceid=chrome&ie=UTF-8


On Tue, Mar 6, 2018 at 9:06 PM, Miles <email address hidden> wrote:

> I'm also seeing this issue and I just purged Duplicity and then added it
> back with the PPA and I am still seeing the issue. I am using 0.7.17
> now. What information can I provide to help fix this?
>
> Ubuntu Version: UbuntuMate 17.10
>
> uname -a
> Linux 4.13.0-36-generic #40-Ubuntu SMP Fri Feb 16 20:07:48 UTC 2018 x86_64
> x86_64 x86_64 GNU/Linux
>
> ulimit -v
> unlimited
>
> ulimit -a
> core file size          (blocks, -c) 0
> data seg size           (kbytes, -d) unlimited
> scheduling priority             (-e) 0
> file size               (blocks, -f) unlimited
> pending signals                 (-i) 31429
> max locked memory       (kbytes, -l) 64
> max memory size         (kbytes, -m) unlimited
> open files                      (-n) 1024
> pipe size            (512 bytes, -p) 8
> POSIX message queues     (bytes, -q) 819200
> real-time priority              (-r) 0
> stack size              (kbytes, -s) 8192
> cpu time               (seconds, -t) unlimited
> max user processes              (-u) 31429
> virtual memory          (kbytes, -v) unlimited
> file locks                      (-x) unlimited
>
> --
> You received this bug notification because you are subscribed to
> duplicity in Ubuntu.
> https://bugs.launchpad.net/bugs/1727653
>
> Title:
>   error: can't start new thread
>
> Status in Duplicity:
>   Incomplete
> Status in deja-dup package in Ubuntu:
>   Triaged
> Status in duplicity package in Ubuntu:
>   In Progress
>
> Bug description:
>   $ uname -a
>   Linux mbpr13b 4.13.0-16-generic #19-Ubuntu SMP Wed Oct 11 18:35:14 UTC
> 2017 x86_64 x86_64 x86_64 GNU/Linux
>
>   duplicity gets started daily via deja-dup automatically.
>
>   Every now and then (approx. every third time) I get the following
>   error:
>
>   ------------------
>
>   Failed with an unknown error.
>
>   Traceback (most recent call last):
>     File "/usr/bin/duplicity", line 1546, in <module>
>       with_tempdir(main)
>     File "/usr/bin/duplicity", line 1540, in with_tempdir
>       fn()
>     File "/usr/bin/duplicity", line 1391, in main
>       do_backup(action)
>     File "/usr/bin/duplicity", line 1468, in do_backup
>       restore(col_stats)
>     File "/usr/bin/duplicity", line 731, in restore
>       restore_get_patched_rop_iter(col_stats)):
>     File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line
> 560, in Write_ROPaths
>       for ropath in rop_iter:
>     File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line
> 523, in integrate_patch_iters
>       for patch_seq in collated:
>     File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line
> 389, in yield_tuples
>       setrorps(overflow, elems)
>     File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line
> 378, in setrorps
>       elems[i] = iter_list[i].next()
>     File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line
> 107, in filter_path_iter
>       for path in path_iter:
>     File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line
> 121, in difftar2path_iter
>       tarinfo_list = [tar_iter.next()]
>     File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line
> 339, in next
>       self.set_tarfile()
>     File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line
> 333, in set_tarfile
>       self.current_fp = self.fileobj_iter.next()
>     File "/usr/bin/duplicity", line 768, in get_fileobj_iter
>       manifest.volume_info_dict[vol_num])
>     File "/usr/bin/duplicity", line 811, in restore_get_enc_fileobj
>       fileobj = tdp.filtered_open_with_delete("rb")
>     File "/usr/lib/python2.7/dist-packages/duplicity/dup_temp.py", line
> 119, in filtered_open_with_delete
>       fh = FileobjHooked(path.DupPath.filtered_open(self, mode))
>     File "/usr/lib/python2.7/dist-packages/duplicity/path.py", line 778,
> in filtered_open
>       return gpg.GPGFile(False, self, gpg_profile)
>     File "/usr/lib/python2.7/dist-packages/duplicity/gpg.py", line 202,
> in __init__
>       'logger': self.logger_fp})
>     File "/usr/lib/python2.7/dist-packages/duplicity/gpginterface.py",
> line 374, in run
>       create_fhs, attach_fhs)
>     File "/usr/lib/python2.7/dist-packages/duplicity/gpginterface.py",
> line 420, in _attach_fork_exec
>       process.thread.start()
>     File "/usr/lib/python2.7/threading.py", line 736, in start
>       _start_new_thread(self.__bootstrap, ())
>   error: can't start new thread
>
>   --------------
>
>   Restarting deja-dup manually fixes the problem and the next few days,
>   automatic backup will run correctly until (see above).
>
>   ProblemType: Bug
>   DistroRelease: Ubuntu 17.10
>   Package: duplicity 0.7.12-1ubuntu1
>   ProcVersionSignature: Ubuntu 4.13.0-16.19-generic 4.13.4
>   Uname: Linux 4.13.0-16-generic x86_64
>   ApportVersion: 2.20.7-0ubuntu3
>   Architecture: amd64
>   CurrentDesktop: ubuntu:GNOME
>   Date: Thu Oct 26 10:49:45 2017
>   InstallationDate: Installed on 2017-10-20 (5 days ago)
>   InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Release amd64
> (20171018)
>   SourcePackage: duplicity
>   UpgradeStatus: No upgrade log present (probably fresh install)
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/duplicity/+bug/1727653/+subscriptions
>