pearでパッケージをupgradeするつもりが失敗した

# pear upgrade XML_Util
WARNING: channel "pear.php.net" has updated its protocols, use "pear channel-update pear.php.net" to update
pear/pear dependency package "pear/XML_Util" downloaded version 1.4.3 is not the recommended version 1.4.2, but may be compatible, use --force to install
pear/XML_Util cannot be installed, conflicts with installed packages
No valid packages found
upgrade failed
#

# pear upgrade XML_Util

WARNING: channel "pear.php.net" has updated its protocols, use "pear channel-update pear.php.net" to update

pear/pear dependency package "pear/XML_Util" downloaded version 1.4.3 is not the recommended version 1.4.2, but may be compatible, use --force to install

pear/XML_Util cannot be installed, conflicts with installed packages

No valid packages found

upgrade failed

強制的にupgradeもできるようですが、そこまでする必要もないので今回はやめておきます。