Upgrade from 16.0.4 to 17.0.0 fails #875
Description
On a Raspberry Pi 4, running occ upgrade fails:
docker exec -u www-data -it docker_nextcloud_1 php occ upgrade
Nextcloud or one of the apps require upgrade - only a limited number of commands are available
You may use your browser or the occ upgrade command to do the upgrade
Set log level to debug
Updating database schema
Updated database
Updating ...
An unhandled exception has been thrown:
TypeError: Return value of OCA\DAV\Migration\Version1012Date20190808122342::changeSchema() must implement interface OCP\DB\ISchemaWrapper or be null, none returned in /var/www/html/apps/dav/lib/Migration/Version1012D ate20190808122342.php:115
Stack trace:
#0 /var/www/html/lib/private/DB/MigrationService.php(475): OCA\DAV\Migration\Version1012Date20190808122342->changeSchema(Object(OC\Migration\SimpleOutput), Object(Closure), Array)
#1 /var/www/html/lib/private/DB/MigrationService.php(411): OC\DB\MigrationService->executeStep('1012Date2019080...', false)
#2 /var/www/html/lib/private/legacy/app.php(906): OC\DB\MigrationService->migrate()
#3 /var/www/html/lib/private/Updater.php(373): OC_App::updateApp('dav')
#4 /var/www/html/lib/private/Updater.php(252): OC\Updater->doAppUpgrade()
#5 /var/www/html/lib/private/Updater.php(128): OC\Updater->doUpgrade('17.0.0.9', '16.0.4.1')
#6 /var/www/html/core/Command/Upgrade.php(258): OC\Updater->upgrade()
#7 /var/www/html/3rdparty/symfony/console/Command/Command.php(255): OC\Core\Command\Upgrade->execute(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#8 /var/www/html/3rdparty/symfony/console/Application.php(908): Symfony\Component\Console\Command\Command->run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput) )
#9 /var/www/html/3rdparty/symfony/console/Application.php(269): Symfony\Component\Console\Application->doRunCommand(Object(OC\Core\Command\Upgrade), Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\C omponent\Console\Output\ConsoleOutput))
#10 /var/www/html/3rdparty/symfony/console/Application.php(145): Symfony\Component\Console\Application->doRun(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#11 /var/www/html/lib/private/Console/Application.php(213): Symfony\Component\Console\Application->run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#12 /var/www/html/console.php(97): OC\Console\Application->run()
#13 /var/www/html/occ(11): require_once('/var/www/html/c...')
What can I do?