src/PEAR/Registry.php
function deleteChannel($channel)
    {
        if (PEAR::isError($e = $this->_lock(LOCK_EX))) {
            return $e;
        }

        $ret = $this->_deleteChannel($channel);
        $this->_unlock();
        if ($ret && is_a($this->_config, 'PEAR_Config')) {
            $this->_config->setChannels($this->listChannels());
        }

        return $ret;
    }
function deleteChannel($channel)
    {
        if (PEAR::isError($e = $this->_lock(LOCK_EX))) {
            return $e;
        }

        $ret = $this->_deleteChannel($channel);
        $this->_unlock();
        if ($ret && is_a($this->_config, 'PEAR_Config')) {
            $this->_config->setChannels($this->listChannels());
        }

        return $ret;
    }
Deletion fails if there are any packages installed from the channel
@param string|PEAR_ChannelFile channel name
@return boolean|PEAR_Error True on deletion, false if it doesn't exist