Changing the defaults for --localstatedir and --sysconfdir?

Changing the defaults for --localstatedir and --sysconfdir?

[Richard Sent]

Hi Guix,

As everyone who's built Guix from source knows, when running ./configure
on a system with an existing Guix installation you must remember to
specify --localstatedir=/var and --sysconfdir=/etc. I think we should
consider whether those variables should default to those values.

There's been discussion on this in the distant past, see [1]. At risk of
oversimplifying, I think previous consensus was in favor of making some
sort of change over the existing behavior before discussion fizzled.

The reason for the current situation is so if a user builds and installs
Guix from source, localstatedir and sysconfdir will be located in
$prefix/var and $prefix/etc. See [2] for Ludo's comments on the matter,
[3] for the convention of localstatedir and sysconfdir being under
$prefix.

However, the "guix" package packaged with Guix (that's a sentence...)
configures itself with "--localstatedir=/var" and "--sysconfdir=/etc".
See (gnu packages package-management)[guix]. Many (~70) other packages
also use the "--localstatedir=/var" configure flag.

My understanding is this means even if Guix itself was built+installed
from source with the intent of custom Guix-specific var and etc
locations, various Guix-related files will inevitably wind up in /var
anyway. They would either appear from Guix directly or from the packages
Guix installs.

(I've noticed the Guix package'd guix be built in the process of
reconfiguring my system before, although the cause or impact of that
isn't clear to me. It may or may not try placing more files in /var and
/etc.)

As such, if the benefits in [2] aren't achievable (keeping every guix
state-based file in $prefix/var), perhaps it's worth biting the bullet.
Defaulting to /var and /etc would lower the complexity of building Guix.

The number of users manually installing from source is likely lower than
the number of users building Guix for testing purposes. And a user that
wants localstatedir in $prefix/var or sysconfdir in $prefix/etc can
still choose to specify that manually.

If that's not desirable, perhaps there is a third option?

./configure is already smart enough to detect if the configured
localstatedir does not match the installed Guix's localstatedir. How
about a mechanism that follows this process:

1. If ./configure is invoked without localstatedir and/or sysconfdir,
check if there is an existing Guix installation.

2. If there is an existing Guix installation, use the existing
localstatedir and sysconfdir values.

3. If there is not an existing Guix installation, use $prefix/var and
$prefix/etc.

My autotools skill level can be described as asymptotically approaching
0, so that suggestion may or may not be achievable. But I (naively)
think it would satisfy everyone.

Sorry for the wall of text! Congrats on making it to the end. Have a
cookie: 🍪

[1]: https://lists.gnu.org/archive/html/guix-devel/2016-02/msg00718.html
[2]: https://lists.gnu.org/archive/html/guix-devel/2017-09/msg00098.html
[3]: https://www.gnu.org/prep/standards/html_node/Directory-Variables.html
-- 
Take it easy,
Richard Sent
Making my computer weirder one commit at a time.

Re: Changing the defaults for --localstatedir and --sysconfdir?

[Ludovic Courtès]

Hi Richard,

Richard Sent <richard@freakingpenguin.com> skribis:

> As everyone who's built Guix from source knows, when running ./configure
> on a system with an existing Guix installation you must remember to
> specify --localstatedir=/var and --sysconfdir=/etc. I think we should
> consider whether those variables should default to those values.

I think it would make sense.

Before I advocated that we should preferably stick to the GNU standards
and have users make informed choices (that’s how we ended up with the
‘GUIX_CHECK_LOCALSTATEDIR’ macro that warns users but lets them
explicitly pass ‘--localstatedir’.)

That was 8 years ago though (eight!).  At this point I think defaulting
to /var and /etc would do more good than harm.

What do others think?

Thanks,
Ludo’.

Re: Changing the defaults for --localstatedir and --sysconfdir?

[Attila Lendvai]

> What do others think?

i don't really understand all the consequences of this choice... but as a newcomer it surely was strange that i have to use a special incantation that i need to remember, and is added to the documentation, and is explained repeatedly on IRC... instead of making it the default.

good defaults are important. and it's better if the default value causes the least surprise to the ones who know the least.

-- 
• attila lendvai
• PGP: 963F 5D5F 45C7 DFCD 0A39
--
“[…] the real self is dangerous: dangerous for the established church, dangerous for the state, dangerous for the crowd, dangerous for the tradition, because once a man knows his real self, he becomes an individual.”
	— Osho (1931–1990)

Re: Changing the defaults for --localstatedir and --sysconfdir?

[Romain]

On May 2, 2024 8:11:24 AM GMT-01:00, Attila Lendvai <attila@lendvai.name> wrote:
>> What do others think?
>
>i don't really understand all the consequences of this choice... but as a newcomer it surely was strange that i have to use a special incantation that i need to remember, and is added to the documentation, and is explained repeatedly on IRC... instead of making it the default.
>

I totally agree with this too, as a newcomer to Guix and as a person who is setting up new buildtrees somehow frequently.

Romain

Re: Changing the defaults for --localstatedir and --sysconfdir?

[Janneke Nieuwenhuizen]

Ludovic Courtès writes:

> Richard Sent <richard@freakingpenguin.com> skribis:
>
>> As everyone who's built Guix from source knows, when running ./configure
>> on a system with an existing Guix installation you must remember to
>> specify --localstatedir=/var and --sysconfdir=/etc. I think we should
>> consider whether those variables should default to those values.
>
> I think it would make sense.
>
> Before I advocated that we should preferably stick to the GNU standards
> and have users make informed choices (that’s how we ended up with the
> ‘GUIX_CHECK_LOCALSTATEDIR’ macro that warns users but lets them
> explicitly pass ‘--localstatedir’.)
>
> That was 8 years ago though (eight!).  At this point I think defaulting
> to /var and /etc would do more good than harm.
>
> What do others think?

It would be certainly convenient for many us but there should probably a
warning or an error? (cc: @Vagrant) when not on Guix System?

Greetings
Janneke

-- 
Janneke Nieuwenhuizen <janneke@gnu.org>  | GNU LilyPond https://LilyPond.org
Freelance IT https://www.JoyOfSource.com | Avatar® https://AvatarAcademy.com

Re: Changing the defaults for --localstatedir and --sysconfdir?

[Vagrant Cascadian via Development of GNU Guix and the GNU System distribution.]

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On 2024-05-02, Janneke Nieuwenhuizen wrote:
> Ludovic Courtès writes:
>
>> Richard Sent <richard@freakingpenguin.com> skribis:
>>
>>> As everyone who's built Guix from source knows, when running ./configure
>>> on a system with an existing Guix installation you must remember to
>>> specify --localstatedir=/var and --sysconfdir=/etc. I think we should
>>> consider whether those variables should default to those values.
>>
>> I think it would make sense.
>>
>> Before I advocated that we should preferably stick to the GNU standards
>> and have users make informed choices (that’s how we ended up with the
>> ‘GUIX_CHECK_LOCALSTATEDIR’ macro that warns users but lets them
>> explicitly pass ‘--localstatedir’.)
>>
>> That was 8 years ago though (eight!).  At this point I think defaulting
>> to /var and /etc would do more good than harm.
>>
>> What do others think?
>
> It would be certainly convenient for many us but there should probably a
> warning or an error? (cc: @Vagrant) when not on Guix System?

I think /var and /etc would be saner defaults from Debian's perspective
for --localstatedir and --sysconfdir.

That said, all my workflows for passing this are either building the
Debian package (for which it explicitly passes /var and /etc) and
building guix for use with "./pre-inst-env guix ..." for both of those
use cases seem /var and /etc on my systems.

I am not sure what workflows might break by changing the defaults; some
people and systems still use /usr/local for locally built software, such
as FreeBSD ports and similar systems. Not sure how relevent they are to
guix at this point, at least...


live well,
  vagrant

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Re: Changing the defaults for --localstatedir and --sysconfdir?

[Andreas Enge]

Am Thu, May 02, 2024 at 11:00:15AM +0200 schrieb Ludovic Courtès:
> That was 8 years ago though (eight!).  At this point I think defaulting
> to /var and /etc would do more good than harm.
> What do others think?

I have always been in favour of /var and /etc as defaults, and
unsurprisingly still am. That would make the "technical" default coincide
with the "social" default.

Another option discussed at the time, but which would require to start from
scratch in a sense, is to have everything Guix related under /gnu. I have
always found it weird that the database registering the contents of
/gnu/store was not close to /gnu/store; by moving it into /gnu, one could
delete/backup/restore the directory easily.

Andreas

Re: Changing the defaults for --localstatedir and --sysconfdir?

[Efraim Flashner]

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On Thu, May 02, 2024 at 02:58:39PM +0200, Andreas Enge wrote:
> Am Thu, May 02, 2024 at 11:00:15AM +0200 schrieb Ludovic Courtès:
> > That was 8 years ago though (eight!).  At this point I think defaulting
> > to /var and /etc would do more good than harm.
> > What do others think?
> 
> I have always been in favour of /var and /etc as defaults, and
> unsurprisingly still am. That would make the "technical" default coincide
> with the "social" default.
> 
> Another option discussed at the time, but which would require to start from
> scratch in a sense, is to have everything Guix related under /gnu. I have
> always found it weird that the database registering the contents of
> /gnu/store was not close to /gnu/store; by moving it into /gnu, one could
> delete/backup/restore the directory easily.

It certainly would be nice to have everything Guix related under /gnu,
then we could also have the option of giving it its own btrfs subvolume.

-- 
Efraim Flashner   <efraim@flashner.co.il>   רנשלפ םירפא
GPG key = A28B F40C 3E55 1372 662D  14F7 41AA E7DC CA3D 8351
Confidentiality cannot be guaranteed on emails sent or received unencrypted

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Re: Changing the defaults for --localstatedir and --sysconfdir?

[Ludovic Courtès]

Efraim Flashner <efraim@flashner.co.il> skribis:

> On Thu, May 02, 2024 at 02:58:39PM +0200, Andreas Enge wrote:
>> Am Thu, May 02, 2024 at 11:00:15AM +0200 schrieb Ludovic Courtès:
>> > That was 8 years ago though (eight!).  At this point I think defaulting
>> > to /var and /etc would do more good than harm.
>> > What do others think?
>> 
>> I have always been in favour of /var and /etc as defaults, and
>> unsurprisingly still am. That would make the "technical" default coincide
>> with the "social" default.
>> 
>> Another option discussed at the time, but which would require to start from
>> scratch in a sense, is to have everything Guix related under /gnu. I have
>> always found it weird that the database registering the contents of
>> /gnu/store was not close to /gnu/store; by moving it into /gnu, one could
>> delete/backup/restore the directory easily.
>
> It certainly would be nice to have everything Guix related under /gnu,
> then we could also have the option of giving it its own btrfs subvolume.

Maybe, but that’s a much too complicated change…

Ludo’.

Re: Changing the defaults for --localstatedir and --sysconfdir?

[Efraim Flashner]

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On Thu, May 02, 2024 at 11:00:15AM +0200, Ludovic Courtès wrote:
> Hi Richard,
> 
> Richard Sent <richard@freakingpenguin.com> skribis:
> 
> > As everyone who's built Guix from source knows, when running ./configure
> > on a system with an existing Guix installation you must remember to
> > specify --localstatedir=/var and --sysconfdir=/etc. I think we should
> > consider whether those variables should default to those values.
> 
> I think it would make sense.
> 
> Before I advocated that we should preferably stick to the GNU standards
> and have users make informed choices (that’s how we ended up with the
> ‘GUIX_CHECK_LOCALSTATEDIR’ macro that warns users but lets them
> explicitly pass ‘--localstatedir’.)
> 
> That was 8 years ago though (eight!).  At this point I think defaulting
> to /var and /etc would do more good than harm.
> 
> What do others think?

I think changing the defaults to use /var and /etc by default would be a
good change.  If someone needs to use the /usr/local/{var,etc}
directories they're able to change back to the previous defaults
themselves.

-- 
Efraim Flashner   <efraim@flashner.co.il>   רנשלפ םירפא
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Confidentiality cannot be guaranteed on emails sent or received unencrypted

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Re: Changing the defaults for --localstatedir and --sysconfdir?

[Felix Lechner via Development of GNU Guix and the GNU System distribution.]

Hi everyone,

On Thu, May 02 2024, Efraim Flashner wrote:

> changing the defaults to use /var and /etc by default would be a good
> change.

If that's too complicated, someone could alternatively add

    ./configure --localstatedir=/var --sysconfdir=/etc

to ./bootstrap.

People needing different settings could then run ./configure again.

Kind regards
Felix

Re: Changing the defaults for --localstatedir and --sysconfdir?

[Maxim Cournoyer]

Hi,

Felix Lechner via "Development of GNU Guix and the GNU System
distribution." <guix-devel@gnu.org> writes:

> Hi everyone,
>
> On Thu, May 02 2024, Efraim Flashner wrote:
>
>> changing the defaults to use /var and /etc by default would be a good
>> change.
>
> If that's too complicated, someone could alternatively add
>
>     ./configure --localstatedir=/var --sysconfdir=/etc
>
> to ./bootstrap.

In case someone missed it, the above is now the default (/var and /etc),
since commit 77771036f0970083c146b709d792d128f4235125 ("configure.ac:
Set default value for the 'prefix' variable.").

You can thus finally forget to use --localstatedir=/var
--sysconfdir=/etc when running the configure script.

-- 
Thanks,
Maxim

Re: Changing the defaults for --localstatedir and --sysconfdir?

[Ricardo Wurmus]

Ludovic Courtès <ludo@gnu.org> writes:

> At this point I think defaulting
> to /var and /etc would do more good than harm.

Are those the only defaults that should change?  These are the only ones
we are actively using, but perhaps it would be confusing to have
--prefix still point to /usr/local whereas --localstatedir and
--sysconfdir point to something appropriate for --prefix=/.

(I'm in favor of setting the expected defaults for --localstatedir and
--sysconfdir.)

-- 
Ricardo

Re: Changing the defaults for --localstatedir and --sysconfdir?

[Ludovic Courtès]

Hi,

Ricardo Wurmus <rekado@elephly.net> skribis:

> Ludovic Courtès <ludo@gnu.org> writes:
>
>> At this point I think defaulting
>> to /var and /etc would do more good than harm.
>
> Are those the only defaults that should change?  These are the only ones
> we are actively using, but perhaps it would be confusing to have
> --prefix still point to /usr/local whereas --localstatedir and
> --sysconfdir point to something appropriate for --prefix=/.

Good point.  Maybe we should in fact change the default prefix instead
of just localstatedir and sysconfdir?

Ludo’.

Re: Changing the defaults for --localstatedir and --sysconfdir?

[Simon Tournier]

Hi,

On jeu., 02 mai 2024 at 11:00, Ludovic Courtès <ludo@gnu.org> wrote:
> Richard Sent <richard@freakingpenguin.com> skribis:
>
>> As everyone who's built Guix from source knows, when running ./configure
>> on a system with an existing Guix installation you must remember to
>> specify --localstatedir=/var and --sysconfdir=/etc. I think we should
>> consider whether those variables should default to those values.
>
> I think it would make sense.

I have always been for changing the defaults but GNU standards…

> Before I advocated that we should preferably stick to the GNU standards
> and have users make informed choices (that’s how we ended up with the
> ‘GUIX_CHECK_LOCALSTATEDIR’ macro that warns users but lets them
> explicitly pass ‘--localstatedir’.)

…and I have never understood this argument. :-)


Well, these GNU Standards read:

  ‘sysconfdir’

     [...]

      This directory should normally be /usr/local/etc, but write it as
      $(prefix)/etc. (If you are using Autoconf, write it as
      ‘@sysconfdir@’.)

  ‘localstatedir’

      [...]

      $(localstatedir) should normally be /usr/local/var, but write it
      as $(prefix)/var. (If you are using Autoconf, write it as
      ‘@localstatedir@’.)

    https://www.gnu.org/prep/standards/standards.html#Directory-Variables


As Ricardo pointed, it could be confusing to have some defaults as GNU
Standards recommend and only 2 different.  Especially, $(prefix) might
appear elsewhere as recommendation: ’exec_prefix’ so then ’bindir’,
’sbindir’ etc., ‘datarootdir’ so ’datadir’, ‘sharedstatedir’,
‘includedir’, etc.

Therefore, setting also by default ’prefix’ as /. would mean ’bindir’
equals to /bin.  That’s fine… we need to adjust accordingly
guix-install.sh, to my knowledge.

Well, this ’prefix’ default matters only in one case: other distro
packaging Guix, right?

And I guess these distro do not run “make install” with the default GNU
Standards ’prefix’ recommendation (/usr/local/bin/) and modifies it to
/usr/, I guess.

On foreign distro:

        $ ls -a /usr/local/bin/
        .  ..  guix

This ’guix’ comes from guix-install.sh.

All in all, the surprise when defaulting ’prefix’, ’localstatedir’ and
’sysconfdir’ should be very limited, no?

Cheers,
simon