TYPO3 Core

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:

http://pecl.php.net/bugs/bug.php?id=16721

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)