In addition to building filesystem images, a common use of root for operating system building is to chroot into a "clean" environment to avoid environmental cor

In addition to building filesystem images, a common use of root for operating system building is to chroot into a "clean" environment to avoid environmental corruption. (In general, chroot is reserved to uid 0 due to issues with setuid binaries -- on some systems chroot can be made available to non-root users by turning off setuid behaviour.)