Before creating your target-system, you sometimes need to setup your build-environment. E.g. if you want to use the uClibc-libraries, you have to compile the uClibc-source and install the uClibc-utility wrappers.
Creating the build-environment is a straightforward extension to the mechanisms used to create filesystems. Building is done by processing environment-packages. All environment-packages are located below DIST_ROOT/src/packages/env. The default is to process all subdirectories below DIST_ROOT/src/packages/env, but you can also set the variable env_PACKAGES with a blank-separated list of packages. This is especially useful if order is relevant.
Environment-packages must define the target env-install. See "packages" for details.