Hi,
under Ubuntu 12.04 all you need to do is:
sudo add-apt-repository ppa:paparazzi-uav/ppa
sudo apt-get update
sudo apt-get install paparazzi-dev
If you want to use Paparazzi v4.x or earlier versions:
sudo apt-get install paparazzi-arm-multilib
Or if you want to use Paparazzi v5.0 or later and also want support for STM32F4 MCUs, install the gcc-arm-embedded toolchain.
or install the binary package from either the "official" ppa:
sudo add-apt-repository ppa:terry.guo/gcc-arm-embedded
Or if you want Python support in GDB, you can use mine:
sudo add-apt-repository ppa:flixr/gcc-arm-embedded
Then install the gcc-arm-none-eabi package:
sudo apt-get update
sudo apt-get install gcc-arm-none-eabi
If you want to use JSBSim:
sudo apt-get install paparazzi-jsbsim
There should be no need to "manually" install other packages to compile Paparazzi.
If you do get some errors, please post the full output with details of which packages you installed and which paparazzi_version you are using.
Cheers, Felix