I've installed PHP 5.6 from the PPA
All the packages are called php5.6-whatever.
There is no php5.6-pear in that PPA.
How can I install php5.6-pear?
I had the same problem. Installing php5.6-dev package and adjusting the default php binaries like described in https://github.com/oerdnj/deb.sury.org/wiki/PECL-Installation did it for me:
apt-get install php5.6-dev update-alternatives --set php /usr/bin/php5.6 update-alternatives --set php-config /usr/bin/php-config5.6 update-alternatives --set phpize /usr/bin/phpize5.6
Then it will work like expected:
pecl channel-update pecl.php.net Updating channel "pecl.php.net" Update of Channel "pecl.php.net" succeeded