sudo apt-get install -y php5.5
安裝出現錯誤
升級系統之後php版本太高程式出錯誤
所以要降到5.5，但是無法安裝
有人有ubuntu 16安裝php5.5的經驗嗎?

ubuntu@ip-172-32-0-93:~$ sudo apt-get install -y php5.5
Reading package lists... Done
Building dependency tree
Reading state information... Done
Note, selecting 'php5.5-libsodium' for regex 'php5.5'
Note, selecting 'php5.5-tideways' for regex 'php5.5'
Note, selecting 'php5.5-xhprof' for regex 'php5.5'
Note, selecting 'php5.5-gmagick' for regex 'php5.5'
Note, selecting 'php5.5-smbclient' for regex 'php5.5'
Note, selecting 'php5.5-mongo' for regex 'php5.5'
Note, selecting 'php5.5-geoip' for regex 'php5.5'
Note, selecting 'php5.5-uuid' for regex 'php5.5'
Note, selecting 'php5.5-oauth' for regex 'php5.5'
Note, selecting 'php5.5-radius' for regex 'php5.5'
Note, selecting 'php5.5-rrd' for regex 'php5.5'
Note, selecting 'php5.5-memcache' for regex 'php5.5'
Note, selecting 'php5.5-uploadprogress' for regex 'php5.5'
Note, selecting 'php5.5-xcache' for regex 'php5.5'
Note, selecting 'php5.5-yac' for regex 'php5.5'
Note, selecting 'php5.5-yaml' for regex 'php5.5'
Note, selecting 'php5.5-zmq' for regex 'php5.5'
Note, selecting 'php5.5-raphf' for regex 'php5.5'
Note, selecting 'php5.5-propro' for regex 'php5.5'
Note, selecting 'php5.5-amqp' for regex 'php5.5'
Note, selecting 'php-radius' instead of 'php5.5-radius'
Note, selecting 'php-uploadprogress' instead of 'php5.5-uploadprogress'
Note, selecting 'php-yaml' instead of 'php5.5-yaml'
Note, selecting 'php-amqp' instead of 'php5.5-amqp'
Note, selecting 'php-rrd' instead of 'php5.5-rrd'
Note, selecting 'php-uuid' instead of 'php5.5-uuid'
Note, selecting 'php-memcache' instead of 'php5.5-memcache'
Note, selecting 'php-gmagick' instead of 'php5.5-gmagick'
Note, selecting 'php-smbclient' instead of 'php5.5-smbclient'
Note, selecting 'php-zmq' instead of 'php5.5-zmq'
Note, selecting 'php-geoip' instead of 'php5.5-geoip'
Note, selecting 'php-tideways' instead of 'php5.5-tideways'
Note, selecting 'php-yac' instead of 'php5.5-yac'
Note, selecting 'php-libsodium' instead of 'php5.5-libsodium'
Note, selecting 'php-oauth' instead of 'php5.5-oauth'
Note, selecting 'php-propro' instead of 'php5.5-propro'
Note, selecting 'php-raphf' instead of 'php5.5-raphf'
Note, selecting 'php-xcache' instead of 'php5.5-xcache'
Note, selecting 'php-mongo' instead of 'php5.5-mongo'
Note, selecting 'php-xhprof' instead of 'php5.5-xhprof'
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
php-yac : Conflicts: php-xcache but 3.2.0-2+deb.sury.org~xenial+1 is to be installed
E: Unable to correct problems, you have held broken packages.