* build-aux/update-guix-package.scm (main): Define 'root', and call 'add-indirect-root' to protect SOURCE from GC.
* build-aux/update-guix-package.scm: New file. * Makefile.am (EXTRA_DIST): Add it. (update-guix-package): New target. (.PHONY): Add it. * gnu/packages/package-management.scm (guix): Mention it.