# Hacking on the GN binary itself ## Building GN itself GN is part of the Chromium tree, in [//tools/gn/](../). If you have a Chromium checkout, you already have the source and you can do `ninja -C out/Debug gn` to build it. To build gn using gn, run (in the root `src` directory): ``` gn gen out/Default ninja -C out/Default gn ``` Change `out/Default` as necessary to put the build directory where you want. ## Running GN's unit tests ``` ninja -C out/Default gn_unittests && out/Default/gn_unittests ```