libqgis-dev software package provides QGIS - development files, 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 libqgis-dev
libqgis-dev is installed in your system.
Make ensure the libqgis-dev package were installed using the commands given below,
$ sudo dpkg-query -l | grep libqgis-dev *
You will get with libqgis-dev package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | Library development |
| Package | libqgis-dev |
| Version | 2.0.1-2build2 |
| Description | QGIS - development files |
| Sub Section | libdevel |