Debian maintainers changed default Apache from version 2.2 to 2.4. Not a big deal?

I was just upgrading one package and it had dependency on whole new Apache. I said yes to upgrade, because I had no bigger issues with Apache upgrade in past.

Wohoo. This upgrade was very funny, because Apache 2.4 was not able to start due to conflicting configurations. The coolest part was that Subversion stopped working, but that’s different story.

The problematic part was that Apache failed to start with nice message:

[FAIL] Starting web server: apache2 failed!
[warn] The apache2 instance did not start within 20 seconds. Please read the log files to discover problems ... (warning)

I checked the log file /var/log/apache2/error.log, but there was no hint what went wrong.

Apache was working even though startup script reported error. :-)

After a while I found that there were some important changes in /etc/apache2/apache2.conf. I compared this file with /etc/apache2/apache2.conf.dpkg.dist.

It was necessary to update following lines in apache2.conf:

Mutex file:${APACHE_LOCK_DIR} default
PidFile ${APACHE_PID_FILE}
#LockFile /var/lock/apache2/accept.lock - disable this, old value

Then it was possible to start Apache without problem:

[ ok ] Restarting web server: apache2.