Re: Guile 3 migration plan

["Ludovic Courtès" <ludo@gnu.org>]

Hello!

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

> On Thu, Jan 16, 2020 at 11:08:15AM +0100, Ludovic Courtès wrote:
>> Hello Guix!
>> 
>> Today is Guile 3 day, a day to celebrate, woohoo!  \o/
>> 
>> How will Guix migrate to Guile 3?  That’s a threefold process:
>> 
>>   1. We must first migrate packages.  I propose to rename “guile-next”
>>      to “guile” today, such that “guix install guile” will now install
>>      Guile 3 (no mass rebuild involved: the “default” Guile remains
>>      2.2.)
>> 
>>      The downside is that if you run “guix install guile guile-json”,
>>      you’ll get Guile 3 with Guile-JSON for 2.2; instead, you have to
>>      explicitly select “guile3.0-json”.
>
> I feel like these should move together. Imagine if we had python
> libraries that only worked with python2 but called them python-foo
> anyway. Having consistent naming between the packages is important.

Note that it means that a number of “guile-” packages (those that do not
work yet with Guile 3) will disappear or be temporarily superseded by a
“guile2.2-” package, which again will not work with Guile 3.

So it’s not a great solution either; people may still have to explicitly
select guile@2 or something.

WDYT?

Now, whatever we choose, we can add an entry to ‘etc/news.scm’ to make
the transition smoother.

>>      I propose renaming all the “guile3.0-” packages to “guile-”, and
>>      all the “guile-” packages to “guile2.2-” as a second step, which
>>      will address this issue.  This could be done within a few days or
>>      weeks.
>
> It seems to me we could switch the guile packages to guile3.0 and leave
> guix at guile2.2. In any case, we should create a guix-with-guile3
> package to encourage people to try to fix bugs and try it out.

Sure.

>>   2. We must be able to run Guix itself on Guile 3.  This is already
>>      possible if you add “3.0” to the ‘GUILE_PKG’ invocation in
>>      ‘configure.ac’, but there are still a few test failures that I’ve
>>      been working on.  Almost all of them relate to the use of ‘@@’ and
>>      ‘mock’, which do not work with Guile 3 “declarative modules”.
>> 
>>      In many cases, it’s an opportunity to clean up our tests; see for
>>      example 4aea90b1876179aab8d603a42533a6bdf97ccd3c and the preceding
>>      commit.  It should be possible to be done real soon!
>
> I'm going to miss '@@'

It’s still there, it just doesn’t give you what you want in some cases.

Anyhow, happy Guile 3 day!  :-)

Ludo’.