### 5.2.2. `build/conf/local.conf`

This file contains all the local user configuration for your build environment. If there is no `local.conf` present, it is created from `local.conf.sample`. The `local.conf` file contains documentation on the various configuration options. Any variable set here overrides any variable set elsewhere within the environment unless that variable is hard-coded within a file (e.g. by using '=' instead of '?='). Some variables are hard-coded for various reasons but these variables are relatively rare.

Edit this file to set the `MACHINE` for which you want to build, which package types you wish to use (`PACKAGE_CLASSES`), where you want to downloaded files (`DL_DIR`), and how you want your host machine to use resources (`BB_NUMBER_THREADS` and `PARALLEL_MAKE`).