[horde] How to upgrade - was: Horde 5.0.0alpha1

[Stephan]

> I saw that an uninstall & install changed from stable to alpha. So
> finaly I tried and solved it with:
>
>    ...upgrade horde/horde-alpha --alldeps

I did the same to upgrade a running horde4 system to 5 alpha. When I try 
to access it I get error messages depending on whether I copy 
config/conf.php.dist to config/conf.php or not:

With config/conf.php:

Fatal error: Call to undefined method Horde_Registry::getView() in 
/var/www/horde4/index.php on line 73

Without config/conf.php:

Warning: set_exception_handler() expects the argument 
(Horde_ErrorHandler::fatal) to be a valid callback in 
/var/www/horde4/lib/core.php on line 54 Warning: set_error_handler() 
expects the argument (Horde_ErrorHandler::errorHandler) to be a valid 
callback in /var/www/horde4/lib/core.php on line 57 Notice: Undefined 
index: max_exec_time in /usr/share/php/Horde/Registry.php on line 389 
Notice: Undefined index: debug_level in 
/usr/share/php/Horde/Registry.php on line 394

Any thoughts ?

Regards
Stephan