From 067a2e2de9e5f8437ce020c62f64e08b82af72b8 Mon Sep 17 00:00:00 2001 From: Chris Marusich Date: Fri, 2 Dec 2016 01:52:04 -0800 Subject: [PATCH] guix system: If the new system generation already exists, overwrite it. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fixes . Before that, 'guix system reconfigure' would fail if the next generation already existed. * guix/scripts/system.scm (switch-to-system): Use 'switch-symlink' instead of 'symlink'. * doc/guix.texi (Using the Configuration System, Invoking guix system): Document the behavior. Signed-off-by: Ludovic Courtès --- doc/guix.texi | 16 +++++++++++++++- guix/scripts/system.scm | 2 +- 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/doc/guix.texi b/doc/guix.texi index 4d7f96d9077999a0e094763f566877e67a6fd509..5c94a56c014bd87b29fba095a6032f23643a5b3c 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -7174,7 +7174,15 @@ modifying or deleting previous generations. Old system generations get an entry in the GRUB boot menu, allowing you to boot them in case something went wrong with the latest generation. Reassuring, no? The @command{guix system list-generations} command lists the system -generations available on disk. +generations available on disk. It is also possible to roll back the +system via the commands @command{guix system roll-back} and +@command{guix system switch-generation}. + +Although the command @command{guix system reconfigure} will not modify +previous generations, must take care when the current generation is not +the latest (e.g., after invoking @command{guix system roll-back}), since +the operation might overwrite a later generation (@pxref{Invoking guix +system}). @unnumberedsubsubsec The Programming Interface @@ -12599,6 +12607,12 @@ currently running; if a service is currently running, it does not attempt to upgrade it since this would not be possible without stopping it first. +This command creates a new generation whose number is one greater than +the current generation (as reported by @command{guix system +list-generations}). If that generation already exists, it will be +overwritten. This behavior mirrors that of @command{guix package} +(@pxref{Invoking guix package}). + It also adds a GRUB menu entry for the new OS configuration, and moves entries for older configurations to a submenu---unless @option{--no-grub} is passed. diff --git a/guix/scripts/system.scm b/guix/scripts/system.scm index bb373a6726ecbab02d6b085672cee1881f31c347..144a7fd377c64dc571233c6a49462ef8aa4a8b24 100644 --- a/guix/scripts/system.scm +++ b/guix/scripts/system.scm @@ -326,7 +326,7 @@ it atomically, and then run OS's activation script." (let* ((system (derivation->output-path drv)) (number (+ 1 (generation-number profile))) (generation (generation-file-name profile number))) - (symlink system generation) + (switch-symlinks generation system) (switch-symlinks profile generation) (format #t (_ "activating system...~%"))