In cases like that we use a mechanism called "grafting". See http://www.gnu.org/software/guix/manual/en/html_node/Security-Updates.html http://www.gnu.org/soft

In cases like that we use a mechanism called "grafting". See http://www.gnu.org/software/guix/manual/en/html_node/Security-Updates.html http://www.gnu.org/software/guix/manual/en/html_node/Securit... for a description. We usually put changes that cause the world to be rebuilt on a separate branch and have the build farm build binaries for it. This can take quite a while, but it's not something a user generally needs to worry about.