Fatal error when installing TYPO3 with PHP-APC (no session is stored)
When installing TYPO3 together on a system with loaded PHP-APC, e.g. the one that ships with Debian Squeeze (APC 3.1.3, but affected seems to be also 3.1.4-dev, 3.1.3p1, 3.1.2, 3.0.19) you get a Fatal error.
On the first step of the install tool:
Fatal error: Class 't3lib_div' not found in /../typo3/sysext/install/mod/class.tx_install_session.php on line 347
See screen in the attachment (Fatal Error on the bottom).
No further steps are then possible (you then get a login screen).
It turns out that the list of loaded classes is incomplete when PHP tries to write the session data. t3lib_div is not there anymore. This behaviour was introduced in #24980.
The PHP bug is already documented and acknoledged by PHP / APC authors:
From the comment from Rasmus
[2011-02-14 16:44 UTC] rasmus at php dot net
Once again, the fix is trivial. Put session_write_close() in
your script when you are done with the session.
We'll come up with a fix eventually, but it isn't a trivial
thing to fix.
Calling session_write_close() at the destructor of the tx_install_session class seems to be the most easy solution.
(issue imported from #M17732)