Today I upgraded to Lion (was on Snow Leopard). My main concern was that the OSX (native) PHP would break and that MySQL server (community) installation would not be compatible. I found an article on the topic at : http://www.september28.co.uk/blog/2011/07/20/fixing-mysql-in-os-x-lion-upgrade/ which eased my nerves so I:

1. Ran Software Update,
2. backed up with Time Machine,
3. repaired disk permissions,
4. and verified my disk.
5. Then purchased Lion in the app store on my mac.
6. Made a backup of my /private/etc/php.ini file
7. Installed Lion
8. Ran Software Update again, e.g. for Java updates

Next, I checked my localhost/phpmyadmin and checked my phpinfo.php files. The article ‘Fixing mysql in OS X Lion upgrade’ (link above) was correct. I needed to:

1. Place my copy of php.ini back to its original location at /private/etc/php.ini
2. Update the php.ini file to change mysqli setting… ;mysqli.default_socket = /var/mysql/mysql.sock mysqli.default_socket = /tmp/mysql.sock

My current LAMP dev projects seem just fine so far. Notes on localhost environment on Lion :

• mysql –version mysql  Ver 14.14 Distrib 5.5.12, for osx10.6 (i386) using readline 5.1
• php –version PHP 5.3.6 with Suhosin-Patch (cli) (built: Jun 16 2011 22:26:57)
• httpd -v Server version: Apache/2.2.19 (Unix)