Under Fedora packaging ssystems you will need php-xml
=> yum install php-xml
This extension requires the libxml PHP extension. This means that passing in --enable-libxml is also required, although this is implicitly accomplished because libxml is enabled by default.
Under Fedora packaging ssystems you will need php-xml
=> yum install php-xml
You also need to check libxml is installed. Check phpinfo() > Dom to see if it is. Bug report filed to get this added here.