Solve of this problem
PHP 5.6.20+ version is not stable and packages maybe incompatible. You should be see in here which version is stable. I want to find specific version of extensions and found in here.
I get with wget debian package of php-gd extension:
wget http://http.us.debian.org/debian/pool/main/p/php5.6/php5.6-gd_5.6.20+dfsg-3_amd64.deb
And install with dpkg:
sudo dpkg - i php5.6-gd_5.6.20+dfsg-3_amd64.deb
It's continue to return error message like this:
dpkg: warning: downgrading php5.6-gd from 5.6.20+dfsg-3+donate.sury.org~trusty+1 to 5.6.20+dfsg-3
(Reading database ... 73009 files and directories currently installed.)
Preparing to unpack .../php5.6-gd_5.6.20+dfsg-3_amd64.deb ...
Unpacking php5.6-gd (5.6.20+dfsg-3) over (5.6.20+dfsg-3+donate.sury.org~trusty+1) ...
dpkg: dependency problems prevent configuration of php5.6-gd:
php5.6-gd depends on php5.6-common (= 5.6.20+dfsg-3); however:
Version of php5.6-common on system is 5.6.20+dfsg-3+donate.sury.org~trusty+1.
php5.6-gd depends on libgd3 (>= 2.1.1); however:
Version of libgd3:amd64 on system is 2.1.0-3.
php5.6-gd depends on libjpeg62-turbo (>= 1.3.1); however:
Package libjpeg62-turbo is not installed.
php5.6-gd depends on libpng16-16 (>= 1.6.2-1); however:
Package libpng16-16 is not installed.
dpkg: error processing package php5.6-gd (--install):
dependency problems - leaving unconfigured
Processing triggers for php5.6-fpm (5.6.20+dfsg-3+donate.sury.org~trusty+1) ...
php5.6-fpm stop/waiting
php5.6-fpm start/running, process 11382
Errors were encountered while processing:
php5.6-gd
This informations say our "php5.6-common" package must be install at system. For fix this problem is this command:
sudo apt-get -f install
After this command will upgrade "php5.6-gd" and installed correct package. I type terminal "php -v" and it's say me everything is good:
PHP 5.6.20-3+donate.sury.org~trusty+1 (cli)
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies
with Zend OPcache v7.0.6-dev, Copyright (c) 1999-2016, by Zend Technologies
with Xdebug v2.4.1-dev, Copyright (c) 2002-2016, by Derick Rethans