Values.PosixUserSourceSpecifies the POSIX identity with uid, gid, and secondary group IDs for user enforcement.
type nonrec t = {uid : Uid.t;The POSIX user ID.
*)gid : Gid.t;The POSIX group ID.
*)secondaryGids : SecondaryGids.t option;An array of secondary POSIX group IDs.
*)}