libgtk-3-dev software package provides development files for the GTK+ library, you can install in your Debian 8 (Jessie) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install libgtk-3-dev
libgtk-3-dev is installed in your system.
Make ensure the libgtk-3-dev package were installed using the commands given below,
$ sudo dpkg-query -l | grep libgtk-3-dev *
You will get with libgtk-3-dev package name, version, architecture and description in a table
| Distro | Debian 8 jessie |
| Section | Library development |
| Package | libgtk-3-dev |
| Version | 3.14.5-1+deb8u1 |
| Description | development files for the GTK+ library |
| Sub Section | Libdevel |