not syncing: no error message, missing storage rights, missing openssh key import, doesn't delete. Tutorial for end-users.

Hi, syncopoli is not syncing anything, and more importantly, there are no or no user-friendly error messages. I got it to work (steps below), and the following sub-bugs appear:

Syncopoli doesn't ask for sdcard rights
It doesn't warn that rsync has never synced
It doesn't warn about sync errors (possibly except server down, didn't test that).
It doesn't import openssh keys automatically. That is important because openssh is the default on most or all linux distributions.
It doesn't delete deleted files, despite that is what newbies are used to from dropbox. At least, Syncopoli should point out this potential pitfall.
Wishlist: easy way to configure lots of source directories in one go. Many Android apps want to write to their own little directories scattered all over /sdcard, and I would like to sync them all as a directory tree. See http://stackoverflow.com/questions/1813907/rsync-delete-files-from-list-dest-does-not-delete-unwanted-files.

This bug report is also a step-by-step tutorial for Ubuntu end users how to get it to work: Do steps (1), (2), (3), (6), (8), (9), (11).

What I did: (1) Install syncopoli v0.2 from Fdroid on a Leagoo M5 phone running Android 6.0 with neither root nor adb access. (2) Configure settings as follows: Server address 192.168.0.1 protocol ssh port 22 user: newdedicateduser additional options: no changes from default private key: /storage/emulated/0/path/to/key/id_rsa, copied directly from id_rsa generated by OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.8, OpenSSL 1.0.1f 6 Jan 2014 Rsync password: (empty) frequency: 1 hour wifi only: yes (3) created local-to-remote profile: origin: /sdcard/myfolder destination: /home/newdedicateduser/ (unsynced files are there.) (4) confirmed with vxconnectbot (ssh client available from fdroid) on the same android device that the credentials are ok (and that everything works server-side). (5) pressed "run all sync tasks" on the device, monitored /var/log/syslog on the Ubuntu server.

Expected: Files sync, or at least an easy-to-understand error message. Result: No files are synced. No error messages client-side. Nothing shows up in the server auth logs, i.e. syncopoli did not attempt a connection. Client-side, tapping the connection brings up a log file with only this one line: Fri Jan 06 23:53:52 GMT+01:00 2017

(6) after reading gitlab issues, granted sdcard file rights via settings -> device -> apps -> syncopoli -> rights. Force-closed and restarted app. Ran all sync tasks again. Expected: file sync or usable error message. Result: still no sync. Server-side, nothing shows up in /var/log/auth.log. Client-side, still only that one line in the logs.

(7) rebooted phone, ran sync tasks again. Result: still no sync. Nothing in the server logs. Client-side logs: Sat Jan 07 00:04:18 GMT+01:00 2017

Error text:

/data/user/0/org.amoradi.syncopoli/files/ssh: Exited: String too long rsync: connection unexpectedly closed (0 bytes received so far) [sender] rsync error: error in rsync protocol data stream (code 12) at io.c(226) [sender=3.1.2]

(8) read https://gitlab.com/fengshaun/syncopoli, googled for dropbearconvert. Ran server-side: sudo apt-get install dropbear dropbearconvert #no such file

(9) Googled even more, found https://bugs.launchpad.net/ubuntu/+source/dropbear/+bug/1009868, ran server-side, transferred result to device and configured filepath as private key: /usr/lib/dropbear/dropbearconvert openssh dropbear .ssh/id_rsa .ssh/dropbear_rsa sudo apt-get remove dropbear

syncopoli settings: private key: /storage/emulated/0/path/to/key/dropbear_rsa,

(10) ran "running all sync tasks" client-side. Finally, the test files sync properly except deleted files.

(11) configured Syncopoli settings: Additional options: -vHrlt --no-perms --delete