If you are using phing for building and deploying projects (and you should), and using Remi repository for PHP 5.3 and related tools for CentOs and RedHat, be prepared to see a problem with phing and build.xml files that use conditions in If. Here is a sample snippet from the build.xml:
<!-- Directory separator based on the current file system -->
<property name="ds" value="\" />
<if>
<equals arg1="${host.fstype}" arg2="UNIX" />
<then>
<property name="ds" value="/" override="yes" />
</then>
</if>
and here is the error:
Error reading project file [wrapped: build.xml:39:20: Error initializing nested element <equals> [wrapped: equals (unknown) doesn't support the 'arg1' attribute.]]
The bug #943 has already been filed in assigned in phing trac, and after a brief chat with devs in IRC channel, it seems like it will be fixed soon (by 2.4.14 release). The best cause of action for now though is reverting back phing 2.4.12.