Regular PEAR installation
The preferred method to install Phing is through PEAR and the Phing PEAR channel. You can install Phing by adding the pear.phing.info channel to your PEAR environment and then installing Phing using the phing channel alias and phing package name:
$> pear channel-discover pear.phing.info $> pear install [--alldeps] phing/phing
Be aware that using "--alldeps" on Windows might result in PECL packages (such as Xdebug) being installed - which usually doesn't work on that platform.
Unable to install!
Some users have reported being unable to install Phing through PEAR:
pear install phing/phing No releases available for package "pear.phing.info/phing" install failed
This can usually be solved by running "pear clear-cache".
You may also want to check to see if "http_proxy" is set correctly (run "pear show-config" to verify).
Make sure that the file bin/phing (non-Windows) or bin\phing.bat (Windows) is located on your PATH.
XAMPP / WAMP
Apparently, in some cases, the PEAR cache present in XAMPP or WAMP installations gets corrupted. One user reported that manually clearing the PEAR cache solved the issue of not being able to install Phing.
"In my installation, the PEAR cache is %APPDATA%\Local\Temp\pear\cache\. I just deleted all of the files in this dir."
The following problem might occur when using XAMPP 1.7.2 (other versions haven't been tested or reported):
I have a build.xml file (attached) which works fine if it lies in C:\xampp and doesn't work if it lies in C:\xampp\htdocs The error which occurs is "Can't locate default task list"
It seems that, in some cases, the XAMPP install saves an incorrect, relative path as the PEAR data_dir setting (such as ".\php\data"), making it unreachable from other directories than the base XAMPP installation directory. To remedy this, use pear config_set data_dir ... to edit the setting, and re-install the Phing package.
Another temporary fix is to add the pear/data directory to your include_path:
<< include_path = ".;D:\xampp\php\PEAR" >> include_path = ".;D:\xampp\php\PEAR;D:\xampp\php\PEAR\data"
More information is available here: ticket #376.