libthumbnailer-dev software package provides development files for thumbnailer, you can install in your Ubuntu 14.04 LTS (Trusty Tahr) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install libthumbnailer-dev
libthumbnailer-dev is installed in your system.
Make ensure the libthumbnailer-dev package were installed using the commands given below,
$ sudo dpkg-query -l | grep libthumbnailer-dev *
You will get with libthumbnailer-dev package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | Library development |
| Package | libthumbnailer-dev |
| Version | 1.1+14.04.20140401.1-0ubuntu1 |
| Description | development files for thumbnailer |
| Sub Section | libdevel |