Set up your environment - Linux

These instructions explain how Linux users set up their Cobalt development environment, fetch a copy of the Cobalt code repository, and build a Cobalt binary. Note that the binary has a graphical client and must be run locally on the machine that you are using to view the client. For example, you cannot SSH into another machine and run the binary on that machine.

  1. Choose where you want to put the depot_tools directory, which is used by the Cobalt code. An easy option is to put them in ~/depot_tools. Clone the tools by running the following command:

    $ cd ~/
    $ git clone
  2. Add your depot_tools directory to the end of your PATH variable. We recommend adding something like this to your .bashrc or .profile file:

    $ PATH=${PATH}:/path/to/depot_tools
  3. Run the following command to install packages needed to build and run Cobalt on Linux:

    $ sudo apt-get install bison build-essential coreutils git gperf \
           libaom-dev libasound2-dev libavformat-dev libavresample-dev \
           libdirectfb-dev libdirectfb-extra libpulse-dev \
           libgl1-mesa-dev libgles2-mesa-dev libvpx-dev libx11-dev \
           libxcomposite-dev libxcomposite1 libxrender-dev libxrender1 \
           libxpm-dev m4 python ruby tar xserver-xephyr xz-utils yasm
  4. Install the latest version of the standard C++ header files (libstdc++). For example:

    sudo apt-get install libstdc++-4.8-dev
  5. Clone the Cobalt code repository. The following git command creates a cobalt directory that contains the repository:

    $ git clone
  6. Modify your path to include the version of Clang that is downloaded in the next step of the instructions. The next step will return an error if this version of Clang is not in your path before it runs.

  7. Build the code by navigating to the src directory in your new cobalt directory and running the following command. You must specify a platform when running this command. On goobuntu, the canonical platform is linux-x64x11.

    You can also use the -C command-line flag to specify a build_type. Valid build types are debug, devel, qa, and gold. If you specify a build type, the command finishes sooner. Otherwise, all types are built.

    $ cobalt/build/gyp_cobalt [-C <build_type>] <platform>
  8. Compile the code from the src/ directory:

    $ ninja -C out/<platform>_<build_type> <target_name>

    The previous command contains three variables:

    1. <platform> is the platform configuration that identifies the platform. As described in the Starboard porting guide, it contains a family name (like linux) and a binary variant (like x64x11), separated by a hyphen.
    2. <build_type> is the build you are compiling. Possible values are debug, devel, qa, and gold. These values are also described in the Starboard porting guide under the required file modifications for the gyp_configuration.gypi file.
    3. <target_name> is the name assigned to the compiled code and it is used to run the code compiled in this step. The most common names are cobalt, nplb, and all:
      • cobalt builds the Cobalt app.
      • nplb builds Starboard's platform verification test suite to ensure that your platform's code passes all tests for running Cobalt.
      • all builds all targets.

    For example:

    ninja -C out/linux-x64x11_debug cobalt

    This command compiles the Cobalt debug configuration for the linux-x64x11 platform and creates a target named cobalt that you can then use to run the compiled code.

  9. Run the compiled code to launch the Cobalt client:

    # Note that 'cobalt' was the <target_name> from the previous step.
    $ out/linux-x64x11_debug/cobalt [--url=<url>]

    The flags in the following table are frequently used, and the full set of flags that this command supports are in cobalt/browser/

    allow_http Indicates that you want to use `http` instead of `https`.
    ignore_certificate_errors Indicates that you want to connect to an https host that doesn't have a certificate that can be validated by our set of root CAs.
    url Defines the startup URL that Cobalt will use. If no value is set, then Cobalt uses a default URL. This option lets you point at a different app than the YouTube app.