Operations such as building a package or running the garbage collector
are all performed by a specialized process, the build daemon, on
behalf of clients. Only the daemon may access the store and its
associated database. Thus, any operation that manipulates the store
goes through the daemon. For instance, command-line tools such as
guix package and
guix build communicate with the
daemon (via remote procedure calls) to instruct it what to do.
The following sections explain how to prepare the build daemon’s environment. See also Substitutes, for information on how to allow the daemon to download pre-built binaries.