How do I really manually (!) upgrade to 1.6x?

I’m currently using Piwik 1.5 and I’m unable to upgrade to 1.6.
I’ve tried the automatic update first by even chmod’ing the whole piwik-directory-tree to 0777 (which is kind of insane IMHO) - but Piwik was insisting that automatic updates were not possible.

Fine. So I tried the manual approach as described in the update documentation.
I made a backup copy of my existing piwik installation, unzipped the and transfered the config files to the new installation. That didn’t work either - there was no “Upgrade required” screen visible as described in the documentation.
So I decided to try the update from the command line - which consequently failed too:

PHP Fatal error:  Exception thrown without a stack frame in Unknown on line 0

There were other users here in the forum which had similar problems but the solutions proposed there do not work for me.
I’ve temporarily removed the custom error handler from the index.php file and got this error:

PHP Fatal error:  Uncaught exception 'Zend_Session_Exception' with message 'Zend_Session is currently marked as read-only.' in /home/website/www-stats/piwik-1.6/libs/Zend/Session/Namespace.php:322
Stack trace:
#0 /home/website/www-stats/piwik-1.6/plugins/Installation/Controller.php(42): Zend_Session_Namespace->__set('currentStepDone', '')
#1 /home/website/www-stats/piwik-1.6/plugins/Installation/Installation.php(49): Piwik_Installation_Controller->__construct()
#2 /home/website/www-stats/piwik-1.6/plugins/Installation/Installation.php(69): Piwik_Installation->getInstallationController()
#3 [internal function]: Piwik_Installation->dispatch(Object(Piwik_Event_Notification))
#4 /home/website/www-stats/piwik-1.6/libs/Event/Dispatcher.php(213): call_user_func_array(Array, Array)
#5 /home/website/www-stats/piwik-1.6/core/PluginsManager.php(458): Event_Dispatcher->addObserver(Array, 'FrontController...')
#6 /home/website/www-stats/piwik-1.6/core/PluginsManager.php(330): Piwik_PluginsManager->addPluginObservers(Object(Piwik_Ins in /home/website/www-stats/piwik-1.6/libs/Zend/Session/Namespace.php on line 322

So I’m now back on 1.5x but since the 1.6-Release seems to contain some important bug fixes I’d really love to update. In fact, all I need would be a pointer to an update-SQL script for the 1.6x release if this is possible.

I appreciate the effort to create an easy upgrade process but reading through the forums I got the impression that it just doesn’t work reliable enough. Therefore, providing a sql script to manually update the database would be good.

There used to be few differents bugs in upgrade which should hopefully be fixed in 1.6 onwards.

however your problem is that the PHP is crashing. It seems to be around Session permission. maybe your session directory in piwik/tmp/sessions/ has not the correct permissions.

If that does not work try to switch to DB sessions as per: Installation - Analytics Platform - Matomo

Does that fix it?

PS: created a ticket in Session directory permission not always checked " · Issue #2767 · matomo-org/matomo · GitHub