我为新项目运行composer install，我感到很恐怖：
the requested PHP extension couchbase is missing from your system. To enable extensions, verify that they are enabled in your .ini files:
所以我试图从官方网站上安装couchbase SDK：
# Only needed during first-time setup:
wget http://packages.couchbase.com/releases/couchbase-release/couchbase-release-1.0-4-amd64.deb
sudo dpkg -i couchbase-release-1.0-4-amd64.deb
# Will install or upgrade packages
sudo apt-get update
sudo apt-get install libcouchbase-dev libcouchbase2-bin build-essential
sudo dpkg -i couchbase-release-1.0-4-amd64.deb后出错：
(Reading database ... 155822 files and directories currently installed.)
Preparing to unpack couchbase-release-1.0-4-amd64.deb ...
Supported platforms are: Debian/wheezy,jessie and Ubuntu/lucid,precise,trusty,xenial
dpkg: error processing archive couchbase-release-1.0-4-amd64.deb (--install):
new couchbase-release package pre-installation script subprocess returned error exit status 1
Errors were encountered while processing:
couchbase-release-1.0-4-amd64.deb
我使用Ubuntu 18.04 LTS和PHP 7.1