Re: The tricky case of "--localstatedir=/var"

[Chris Marusich <cmmarusich@gmail.com>]

Jookia <166291@gmail.com> writes:

> Over the past month a few people (myself included) have been hit by the 'gotcha'
> of not running ./configure with "--localstatedir=/var". It doesn't say this in
> the documentation but I question whether not having it as /var is a sane
> default. I'm sure this is somehow tied to the conventions of /usr/local.

I'm not sure there is a single default that will work for everybody. In
general, a value that is appropriate for one use case will not be
appropriate for a different use case.

For example, the README file in the root directory of Guix's git
repository [1] explains that if you want to re-build and re-install Guix
using a system that already runs Guix, it's important to explicitly set
the localstatedir variable to an appropriate value so that the new Guix
sees the existing items in the store. On GuixSD, I believe the
appropriate value would be "/var". Similarly, the Guix manual also
explains [2] that if you wish to have Guix and Nix share the same store,
you must explicitly set the localstatedir variable to an appropriate
value. According to the manual, if you're using Nix's defaults, then
that's "/nix/var". No single default value will satisfy both of those
use cases; somebody will always have to explicitly specify the
localstatedir.

Therefore, instead of worrying about what the "right" default should be,
perhaps it makes more sense to focus on how the documentation can be
improved. If setting the localstatedir is important, the manual should
explain that. The manual already mentions localstatedir, as shown above,
but perhaps the manual is not clear enough. People do seem to be
tripping over it.

With the aim of improving the documentation, then, I'll ask: what was
your use case? Why did you need to set the localstatedir explicitly? Is
there a place in the manual where, if information about the
localstatedir had been present, you would have realized from the start
that you needed to set it, and you would have understood what the
appropriate value to use was?

Best regards,
Chris

[1] README file: http://git.savannah.gnu.org/cgit/guix.git/tree/README
[2] Info node "(guix) Requirements": https://www.gnu.org/software/guix/manual/html_node/Requirements.html