[bug#47979] [PATCH v5 1/2] installer: Recommend 'ntp-service-type' for non-graphical systems.

[Leo Famulari]

On Fri, Dec 24, 2021 at 01:04:40PM -0500, Leo Famulari wrote:
> We had several bug reports with a root cause of "the clock was
> incorrect" from users who used the installer to install a non-graphical
> Guix System.
> 
> * gnu/installer/services.scm (%system-services): Add the ntp-service-type.
> * gnu/installer/newt/services.scm (run-system-administration-cbt-page): New
> variable.
> (run-services-page): Use run-system-administration-cbt-page when not
> installing a desktop.
> * gnu/installer/tests.scm (choose-services): Add and use a
> choose-misc-service?  procedure.
> * gnu/tests/install.scm (installation-target-os-for-gui-tests)<services>: Add
> ntp-service-type.

This v5 patch series is rebased on current master.

It passes `make check-system TESTS="gui-installed-os"`.

When a desktop environment is not selected, it adds a page to the
installer suggesting NTP, and offering GPM (console mouse).

I would have said that it's ready to go, but commit 6f13881f1e92
"installer: Offer the CUPS printing service." also added a page to the
installer offering NTP, unconditionally. That is because the
run-other-services page that it adds offers all recommended services.

https://git.savannah.gnu.org/cgit/guix.git/commit/?id=6f13881f1e92832023caadb3cb51ce393e685e58

However, that breaks the installation, because NTP is provided by
%desktop-services, and services may not be duplicated in config.scm.

So, we need to adjust the functionality added by 6f13881f1e92. I think
we should only offer NTP when the user does not choose any desktops.

If you'd like to test these patches, you can follow the steps described
previously:

https://debbugs.gnu.org/cgi/bugreport.cgi?bug=47979#14

I still think we need to ensure that NTP is either enabled or suggested
for all installations. I remember the wave of bug reports due to "clock
is wrong" after 1.3.0.