Inside the poky directory, there is a script named oe-init-build-env, which should be used to set up the build environment. The script must be run as shown:

$: source poky/oe-init-build-env [build-directory]

Here, build-directory is an optional parameter for the name of the directory where the environment is set; in case it is not given, it defaults to build. The build-directory is the place where we perform the builds.

It is very convenient to use different build directories. We can work on distinct projects in parallel or different experimental setups without affecting our other builds.