Building FlightGear - Linux

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Revision as of 05:52, 15 July 2010 by Fahim Dalvi (Talk | contribs) (Ubuntu and Debian users: Added link to Gentoo FG building article)

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1rightarrow.png See Building Flightgear for the main article about this subject.

This section describes how to build FlightGear on Linux system.

Compiling FlightGear is not a task for novice users. Thus, if you're a beginner (we all were once) on a platform which binaries are available for, we recommend postponing this task and just starting with the binary distribution to get you flying.

Or if you develop on Ubuntu or Debian, consider trying the script described in Scripted Compilation on Linux Debian/Ubuntu.


Before you can compile FlightGear, you need to have the following installed on your computer:

C++ compiler

These are: c++, cpp, gcc, g++ found under the /usr/bin directory. You will also need to have the tools autoconf and automake1.9 installed.


See FlightGear and Git.

OpenGL support

More specifically, your system needs the support for hardware accelerated graphics. You can check for this by running the following in a command line:

glxinfo | grep direct

Note: To run the above command, you need to have the tool mesa-utils installed.

You should then see:

direct rendering: Yes

This means you are good to go as far as OpenGL support is concerned.

If you see:

direct rendering: No

Don't panic yet. This may just mean some required libraries for hardware accelerated graphic are missing. Go ahead and try installing plib 1.8.5 and its dependencies first. If you still get the above message, then you will need to do some googling and troubleshoot yourself.


FlightGear is dependent on quite a few number of libraries. You do not need to compile all of them yourself, but you will at least need to have their development version installed. For example, the development version for package plib1.8.5 is plib1.8.5-dev.

The dependency is summarized in the following tree. Please note that each library has its own dependencies, and most of these are not shown here.

If you attack the above dependencies in the order listed below, you should be good:

1. Glut. Most distributions include glut packages, although you may have to hunt for them. Make sure you install both the glut and glut-devel packages, otherwise FlightGear may be able to compile but won't run correctly.

2. Zlib. Most distributions install the basic zlib libraries by default, but not the development portions. If you don't have zlib.h, you probably need to install the zlib-devel package for your distribution.

3. Plib - portability libraries and scene graph.

4. OpenSceneGraph

5. SimGear - Simulation support libraries. If you are building FlightGear from Git, you need the Git version of SimGear. If you have strange build errors, one of the first things to check is that you have an up-to-date version of SimGear built and installed.


This is a list of all the apt-get commands I had to do while compiling FG, SG, and OSG on a mostly clean Ubuntu 64 system. It is a list of all the libraries you and your computer needs to compile FG, SG, OSG, and PLib. All you have to do is copy the full command, paste it in Terminal, enter your password, and it will download all the packages for you, and install them too. The full command is at the bottom, and I hope someone finds it useful :) sub-dependencies (dependencies of the dependencies) are not included as they are installed automatically by apt-get. If anyone sees something missing, please add it.

git - to get SG and FG
subversion - to get OSG
build-essential - to build (includes GCC, and other build tools)
cmake - OSG Uses this
ccmake-curses-gui -- OSG Uses this
libpng-dev - to enable FG to use PNG textures
libfreetype6-dev - fonts
libalut-dev - sound
libboost-dev - makes coding for some developers easier
automake - needed by ./ files
autoconf - needed by ./ files
libfltk1.1-dev - You will need this if you will be using FGRun

sudo apt-get install git subversion build-essential cmake libpng-dev libfreetype6-dev
libjpeg-dev libungif4-dev libtiff-dev libxmu-dev libxi-dev libglut3-dev libalut-dev
libboost-dev automake autoconf libfltk1.1-dev

Total size is about 230 MB, depending on what you already have from other applications.

This list might seem a bit short, but the sub-dependencies all add up :) The dependencies will be listed by apt-get when you use the command.


Assuming you are root, do:

cd /usr/local/src

Note: When tracking a fast changing software like FlightGear/Git it is highly advisable to install it in a separate directory. That way one can also easily build and reinstall without being root, which greatly reduces the risk of messing up one's system. To install in a directory of your choice add the --prefix argument to configure. E.g. ./configure --prefix=$HOME/FlightGear. I would recommend installing all of OSG, plib, SimGear and FlightGear with the same prefix.

Getting and compiling SimGear

Step 1:

Clone the SimGear git repository and set it up to track the 'next' branch.

git clone git://

By default after cloning you should have a local next branch that tracks the master next branch. It can be updated it with git pull.

Step 2:

The source code will be downloaded into a directory called simgear.

Next, go into the directory and make preparations for the compilation:

cd simgear

Note that if you don't want to install simgear globally on the system but in a specific directory, you can do so by adding --prefix=/path/to/your/fgInstallation to the ./configure command

Step 3:

Compile and install SimGear by doing:

make; make install

Note: with gcc 4.2 or later,on some platforms, you can get compiling errors about alc.h like:

'<anonymous>' has incomplete type 

take a look at

Getting and compiling FlightGear

Step 1:

Clone the FlightGear git repository and set it up to track the 'next' branch.

git clone git://

By default after cloning you should have a local next branch that tracks the master next branch. It can be updated it with git pull.

Step 2:

Next, go into the folder and make preparations for the compilation:

cd flightgear

Note that if you don't want to install simgear globally on the system but in a specific directory, you can do so by adding --prefix=/path/to/your/fgInstallation to the ./configure command. If you didn't install OSG globally or in the same prefix as SimGear and FlightGear, you have to pass the OSG directory to the configure-command like this:

./configure --prefix=/path/to/fgInstallation --with-osg=/path/to/osg/installation --enable-osgviewer

In this case you have to tell your system where to find the OSG libraries before you can run flightgear:

 export LD_LIBRARY_PATH=/path/to/osgInstallation/lib:$LD_LIBRARY_PATH

Step 3:

Now you can compile and install Flightgear by:

make; make install

Step 4:

Clone the data directory:

git clone git://

The data directory is large (almost 2.5GB) so it will take considerable time to download. There mirror of fgdata that might be faster to download from:

git clone git://

The mirror is synchronized with the master so either will do.

And install it in (or as) /usr/local/share/FlightGear

mv fgdata /usr/local/share/FlightGear

Ubuntu and Debian users

If you wish you can use the Scripted_Compilation_on_Linux_Debian/Ubuntu script to have Flightgear compiled in one shot under both Ubuntu and Debian systems.

Debian users who prefer to build it without script may look at Building_Flightgear_-_Debian. Gentoo users can also use overlays to build FlightGear without much hassle : Building_Flightgear_-_Gentoo.

External links