Providing a path for systemd on gentoo - 'profiles', or 'eselect module'? - WAS Re: [gentoo-user] Debian just voted in systemd for default init system in jessie

[Tanstaafl <tanstaafl@libertytrek.org>]

On 2014-02-20 4:04 PM, Canek Peláez Valdés <caneko@gmail.com> wrote:
> On Thu, Feb 20, 2014 at 2:06 PM, Tanstaafl wrote:
>> Thinking about this more, since apparently using a separate
>> profile may just be 'overkill', how about something simpler, like,
>> for example, using eselect...
>>
>> Something like:
>>
>> # eselect init list
>> Available init systems:
>> [1] OpenRC *
>> [2] systemd
>> [3] runit
>>
>> (whatever choices are supported).

> the switching requires reemerging things because you need to set some
> USE flags and quit others. That's the "difficult" (which is not,
> really) part; if you set the USE flags yourself or via a profile, or
> an eselect module, I don't think the difference matters atall.

Ok, so, since it really is so simple, wouldn't it be easier to implement 
this as an eselect module then, as opposed to creating a bunch of 
separate profiles?

(NOTE: to those who might argue it is so trivial that even adding an 
eselect module is overkill, I would respond:

We have eselect modules for changing active profiles and for switching 
active kernels, and as far as I know, all those do is manage a symlink 
(/etc/portage/make.profile for the active profile, and /usr/src/linux).)

Then, if/when a user attempted to switch, eselect could simply spit out 
a warning message about what precisely would be required to complete the 
switch (and this message could be kept updated if/when these 
requirements change), including scary warnings about breakage if they 
fail to complete the steps necessary, then prompt them for confirmation 
(default [n], so an explicit [y] required to execute the change)?

I'd also suggest throwing in a test for current running kernel config, 
to make sure it fully supports booting with systemd, and maybe a new 
emerge command that can also be maintained to make sure that *all* 
necessary packages are rebuilt?

I know, I know, talk is cheap, but again, if systemd proponents want 
systemd on gentoo to ever become a reasonably simple option (or even 
eventually become the new default), I think it is necessary for these 
tools to be built anyway as part of the vetting process, and ultimately 
to provide as many (automated) safeguards as possible to keep new and 
even existing gentoo users from shooting themselves in the foot when 
installing it.

So, the reason I'm explicitly asking is I'd really like for this thread 
to result in a formal feature request to properly shepherd the addition 
of systemd as an optional init system for gentoo, including managing the 
process of switching to it (and back again if desired).

Thanks to all who participated in this thread...