# Pastebin DDMnz3mS
root@dev:/var/www/html# apt install php5.6-dev php5.6-gd
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  dh-php libpcre16-3 libpcre3 libpcre3-dev libpcre32-3 libpcrecpp0v5 libssl-dev libssl-doc
  php-pear php-xml php7.1-common php7.1-xml pkg-php-tools shtool xml2
The following NEW packages will be installed:
  dh-php libpcre16-3 libpcre3-dev libpcre32-3 libpcrecpp0v5 libssl-dev libssl-doc php-pear
  php-xml php5.6-dev php5.6-gd php7.1-common php7.1-xml pkg-php-tools shtool xml2
The following packages will be upgraded:
  libpcre3
1 upgraded, 16 newly installed, 0 to remove and 5 not upgraded.
Need to get 6,652 kB of archives.
After this operation, 27.9 MB of additional disk space will be used.