Update to 13 fails - core/shipped.json is not available

[gas85]

Looks I solve it:

1. go to your nextcloud installation path, for me it is /var/www/nextcloud and my data user is www-data

   /var/www/nextcloud

2. if you will see something like this, proceed to step 3:

@gas85

ls -lah
total 44K
drwxr-xr-x  7 www-data www-data 4.0K Feb 13 10:12 .
drwxr-xr-x  5 root     root     4.0K Jan 23 12:49 …
drwxr-xr-x 20 www-data www-data 4.0K Feb 13 10:00 apps
drwxr-xr-x  2 www-data www-data 4.0K Feb 13 10:00 config
drwxr-x— 12 www-data www-data 4.0K Feb  5 06:25 data
-rw-r–r--  1 www-data www-data   57 Feb 13 10:00 index.php
-rw-r–r--  1 www-data www-data   57 Feb 13 10:00 public.php
-rw-r–r--  1 www-data www-data   57 Feb 13 10:00 remote.php
-rw-r–r--  1 www-data www-data   57 Feb 13 10:00 status.php
drwxr-xr-x  2 www-data www-data 4.0K Feb 13 10:00 themes
drwxr-xr-x  2 www-data www-data 4.0K Jan 25 14:03 updater

3. Copy all files from Nextcloud update downloaded by Web-Updater to actual nextcloud folder

   cp -rf data/updater-XXXXXXX/downloads/nextcloud/ /var/www/

   (it will be copied into /var/www/nextcloud)

4. for me it was needed to set correct permissions by running

   chown -R www-data:www-data *

5. then I run to start upgrade:

   sudo -u www-data php occ upgrade --no-app-disable --no-interaction

   --no-app-disable - Because I have Problem with apps and do not want to remove/disable them - It is ususally not needed.

   --no-interaction - Beacuse I do not want to answer questions…

   …Checking for update of app workflowengine in appstore
   Checked for update of app “workflowengine” in appstore
   Starting code integrity check…
   Finished code integrity check
   Update successful
   Maintenance mode is kept active
   Reset log level

6. Disable maintenance mode

   sudo -u www-data php occ maintenance:mode --off

7. Its alive!!!

Or everything in 1 command for /var/www/nextcloud installation and do not forget to replace XXXXXX with your NC identifier:
sudo -u www-data -s -- 'cd /var/www/nextcloud && cp -rf data/updater-XXXXXX/downloads/nextcloud/ /var/www/ && php occ upgrade --no-interaction && php occ maintenance:mode --off'

P.S. I have only 2 errors: one is Cron job was executed long time ago and second one is some files inconsistency:
Results
=======
- core
- INVALID_HASH
- .htaccess
- FILE_MISSING
- .user.ini

But this is easy to solve.

Solution: go to your download folder and copy files to nextcloud root:

cd data/updater-XXXXXXXXX/downloads/nextcloud/
sudo -u www-data cp .htaccess /var/www/nextcloud
sudo -u www-data cp .user.ini /var/www/nextcloud

Here we learned how to rescan htaccess:

sudo -u www-data php occ maintenance:update:htaccess