Re: [PATCH 6/6] emacs: Add interface for system generations.

[Alex Kost <alezost@gmail.com>]

Ludovic Courtès (2016-01-12 23:35 +0300) wrote:

> Alex Kost <alezost@gmail.com> skribis:
>
>> * emacs/guix-main.scm (system-generation-boot-parameters)
>> (system-generation-param-alist, system-generation-sexps): New procedures.
>> (entries): Add 'system-generation' entry type.
>> * emacs/guix-messages.el (guix-result-message): Use the same messages
>>   for 'generation' and 'system-generation' entry types.
>> * emacs/guix-ui-system-generation.el: New file.
>> * emacs.am (ELFILES): Add it.
>> * doc/emacs.texi (Emacs Commands): Document new commands.
>> * NEWS: Mention new interface.
>
> [...]
>
>> +Analogously on GuixSD you can also display system generations:
>> +
>> +@table @kbd
>> +@item M-x guix-system-generations
>> +@item M-x guix-last-system-generations
>> +@item M-x guix-system-generations-by-time
>> +@end table
>
> As simple as this.  :-)
>
> And I guess it’s also possible to select generations, delete them, and
> switch to a specific one, as with M-x guix-generations?

Well yes, but only if emacs was started with root privileges.  At first
I was going to remove support for deleting/switching system generations
because of this, but then I left it, as I thought there might exist
users who run emacs from "root" for some reason, and such manipulating
system generations may be useful for them.

> Though maybe it would have to use
> “sudo:localhost:/run/current-system/profile” (via Tramp) to be able to
> modify things.  Maybe it could somehow offer to gain root privileges
> when performing an action?

I don't see how it can be done, since we use a guile REPL to perform
such actions (for example, ‘delete-generations’ procedure from (guix
scripts package) module).  But the REPL is started with the same
privileges as emacs.

-- 
Alex