Gentoo users: emerge does not compile dev-lang/php with --enable-xmlreader by default. To enable this option, add the flag xmlreader to your USE variable and recompile php.
The XMLReader extension is available in PECL as of PHP 5.0.0 and is included and enabled as of PHP 5.1.0 by default. It can be enabled by adding the argument --enable-xmlreader (or --with-xmlreader before 5.1.0) to the configure line.
This extension is enabled by default. It may be disabled by using the following option at compile time: --disable-xmlreader
Gentoo users: emerge does not compile dev-lang/php with --enable-xmlreader by default. To enable this option, add the flag xmlreader to your USE variable and recompile php.
If you are having trouble loading this extension (perhaps with a log message like 'Undefined symbol "dom_node_class_entry"'), make sure that you have xmlreader.so listed AFTER dom.so in php.ini.