Return the list of services with the given NAME (a symbol).

Return a gexp that evaluates to a list of POSIX shell statements defining VARIABLES, a list of environment variable name/value pairs. The returned code ensures variable values are properly quoted.

Return a service that extends TARGET with VALUE. This works by creating a singleton service type NAME, of which the returned service is an instance.

Return a gexp that evaluates to a list of POSIX shell statements defining VARIABLES, a list of variable name/value pairs, as shell variables (not environment variables). The returned code ensures variable values are properly quoted.

Insert EXP, a gexp, in a lexical environment providing the 'shell-single-quote' and 'shell-double-quote' bindings.

If FILE is a Home generation GC root such as "guix-home-42-link", return its corresponding base---e.g., "guix-home". Otherwise return #f.

This is similar to the 'generation-profile' procedure but applied to Home generations.