This prepares for an upcoming change to the Docker images, which improves file permission handling.
See #47767.
git-svn-id: https://develop.svn.wordpress.org/trunk@46320 602fd350-edb4-49c9-b593-d223f7449a82
This allows code running inside the container to know whether it's supposed to be running in `build` or `src`.
See #47767.
git-svn-id: https://develop.svn.wordpress.org/trunk@45885 602fd350-edb4-49c9-b593-d223f7449a82