My suggestion is go with the LTS version unless there is a conflict with a dependency.
On Mon, Mar 27, 2023 at 3:58 PM Matthew Benedict de Detrich <matthew.dedetr...@aiven.io.invalid> wrote: > As we are finding out from the conversation in > https://github.com/apache/incubator-pekko/pull/273 (A PR that involves > updating Jackson version due to CVE's/other complications which forces an > update to Scala 3.2 due to Jackson 2.14.2 only supporting Scala 3.1) a lot > of the source/compiler warnings are from Scala 3.2, not Scala 3.3. > > If the PR lands, this means that the argument for avoiding updating to > Scala 3.3 due to syntax/source incompatibilities is weaker since we are > already forced to do the most of the same changes anyways. Furthermore as > can be seen from Jackson 2.14.2 not supporting older Scala 3 versions it > appears that some of the critical parts of the ecosystem are updating Scala > 3 as it releases new minor versions rather than leaving it at older > versions. > > On Fri, Mar 24, 2023 at 4:15 PM Matthew Benedict de Detrich < > matthew.dedetr...@aiven.io> wrote: > > > > Good point also about 2.12 compatibility. It will become harder to > > support multiple Scala version the more the allowed syntax differs. > > > > The reason why I did the PR was to actually confirm/deny whether this is > > an issue, as shown in the PR its a non issue (assuming that Scala 3.3 > > doesn't add anything more between RC3 and release which is quite likely) > > > > On Fri, Mar 24, 2023 at 3:52 PM Johannes Rudolph < > > johannes.rudo...@gmail.com> wrote: > > > >> Just for the record, I also said not to do anything right now about it > :) > >> > >> Other than that, I mostly agree with Nicolas. Unless we are forced to > >> update Scala 3 we should *not* do it right now. The situation might > >> change in 6-12 months with widespread adoption to Scala 3.3 we might > >> just do it (because everyone does by then and updates will only be > >> available for 3.3 at some point in the future). > >> > >> Good point also about 2.12 compatibility. It will become harder to > >> support multiple Scala version the more the allowed syntax differs. > >> > >> On Fri, Mar 24, 2023 at 1:31 PM Matthew Benedict de Detrich > >> <matthew.dedetr...@aiven.io.invalid> wrote: > >> > > >> > > One precondition to upgrade to newer versions of Scala 3 would be > >> dropping > >> > support for Scala 2.12. > >> > Scala 2.13 at least has support for some of the Scala 3 Syntax with > >> > compiler flags to cross compile. > >> > > >> > Are you talking about support on artifact level or on syntax level? > >> Afaik > >> > there isn't any plan for Scala 3.3 to drop support for Scala 2.13 > >> artifacts > >> > (artifacts are completely separated from supported syntax). If we are > >> > talking about a hypothetical Scala 3 user of Pekko, the Scala3 syntax > >> that > >> > Pekko happens to use will be irrelevant here. In other words, if a > user > >> is > >> > upgrading from Scala 3.1/Scala 3.2 to Scala 3.3 then they will have to > >> > upgrade the syntax of the source code irrespective of Pekko. If we are > >> > talking about difficulties of cross compiling for Scala 3/Scala 2 > within > >> > Pekko itself I think we would have to see if there are any syntax > >> breaking > >> > changes in this regard (I didn't see any for Scala 3.3 but I may have > >> > missed something). Since an RC for Scala 3.3 is out we can pretty > easily > >> > figure out if this is going to be a problem right now. > >> > > >> > I think what Johannes said here is important, which is that currently > >> there > >> > aren't any users of Pekko Scala 3 and because of this we really > >> shouldn't > >> > overthink it. And even then, if we do release Pekko with Scala 3.3 and > >> some > >> > hypothetical user is going to have problems because they haven't > >> upgrade to > >> > Scala 3.3 yet, they can easily use the Pekko Scala 2.13 artifact and > >> since > >> > we are not using any bespoke Scala 3 features in Pekko currently on a > >> > source level the user is actually not going to notice any difference. > >> > > >> > On Fri, Mar 24, 2023 at 1:18 PM Nicolas Vollmar <nvoll...@gmail.com> > >> wrote: > >> > > >> > > IMHO we should use the lowest supported version of Scala 3 to not > >> force > >> > > user to upgrade to newer versions. > >> > > > >> > > Scala 3 continues to deprecate old syntax. Some of it will produce > >> warnings > >> > > in Scala 3.2 and may be removed in 3.3 or later. > >> > > For example > >> > > > >> > https://dotty.epfl.ch/docs/reference/dropped-features/package-objects.html > >> > > or > https://dotty.epfl.ch/docs/reference/changed-features/imports.html > >> > > > >> > > One precondition to upgrade to newer versions of Scala 3 would be > >> dropping > >> > > support for Scala 2.12. > >> > > Scala 2.13 at least has support for some of the Scala 3 Syntax with > >> > > compiler flags to cross compile. > >> > > > >> > > > >> > > > >> > > On Fri, 24 Mar 2023 at 10:26, Matthew Benedict de Detrich > >> > > <matthew.dedetr...@aiven.io.invalid> wrote: > >> > > > >> > > > So some discussions on github are popping up regarding which > Scala 3 > >> > > > version we should pick so I think it's time to discuss this > >> formally on > >> > > the > >> > > > mailing list. > >> > > > > >> > > > As a precursor one thing people need to understand is that the > >> Scala 3 > >> > > > release cycle has changed, quoting from > >> > > > > >> > > > >> > https://github.com/apache/incubator-pekko/issues/6#issuecomment-1302701657 > >> > > > > >> > > > > Scala 2 used epoch.major.minor version convention. Scala 3 has > >> > > > major.minor.patch. > >> > > > > >> > > > > So there is no 3.0/3.1/3.2/etc cross-compilation - the > assumption > >> is > >> > > > that: > >> > > > > >> > > > > * you can compile against the same minor version with backward- > >> and > >> > > > forward-compatibility: 3.1.3 dependency against 3.1.0 code, 3.0.0 > >> > > > dependency against 3.0.1 code, etc > >> > > > > * within the same major version you always have > >> backward-compatibility: > >> > > > 3.1.3 dependency can be used in 3.1.3 project, but also 3.2.0 > >> project and > >> > > > in future against 3.3.0 project > >> > > > > >> > > > This means that if we pick a Scala version, we are essentially > >> forcing > >> > > the > >> > > > potential Scala 3 users of Pekko to bump their Scala 3 version to > >> the > >> > > minor > >> > > > that we decide on. On surface value this means that we should pick > >> the > >> > > > lowest Scala 3 minor version that we can support however there is > >> the > >> > > fact > >> > > > that Scala 3.3 is going to come out soon which will be an LTS > >> release. > >> > > The > >> > > > LTS release means that if any bugs are found after Scala 3.3 for a > >> period > >> > > > of 2 years, they will be backported to Scala 3.3. The big > advantage > >> this > >> > > > brings us, is that it allows us to freely bump Scala 3.3 without > >> breaking > >> > > > our users if any potential bugs are found in the future. If we > >> decide to > >> > > > stick with Scala 3.2 or 3.1 and some bug is found in Scala 3 later > >> on > >> > > that > >> > > > affects us, we will have to update to a version of Scala 3 that > will > >> > > break > >> > > > binary compatibility. This facet is of even more importance when > >> > > > considering our 1.0.x release branches, which are designed to > never > >> break > >> > > > binary/backwards compatibility, i.e. if we do 1.0.x releases with > >> Scala > >> > > > 3.1/3.2 and some critical bug/CVE comes out later we could > >> potentially be > >> > > > forced to update the minor version which would break this > >> > > binary/backwards > >> > > > compatibility, this wouldn't be the case with Scala 3.3 (for a > >> certain > >> > > > period of time). > >> > > > > >> > > > Of course the counter argument to using Scala 3.3 is that it would > >> force > >> > > > all potential Pekko users (and the transitive set of Scala 3 > >> libraries > >> > > for > >> > > > that Pekko user) to also use/support Scala 3.3. Unfortunately its > >> not > >> > > > possible to get download stats from Sonatype for artifacts you > don't > >> > > > maintain, but I wouldn't say its a controversial statement that > the > >> > > amount > >> > > > of people that use Akka long with Scala 3 would be a tiny minority > >> (this > >> > > is > >> > > > also regarding other factors, i.e. the typical demographic of Akka > >> > > users). > >> > > > Ontop of this we need to take into account the delay of current > Akka > >> > > users > >> > > > migrating to Pekko, in other words by the time people migrate to > >> using > >> > > > Pekko the fact that its using Scala 3.3 LTS would likely be a non > >> concern > >> > > > at that point in time. > >> > > > > >> > > > And finally another thing to note is that even in the worst case > >> > > scenario, > >> > > > nothing is stopping users from using Scala 2 artifacts from within > >> Scala > >> > > 3 > >> > > > (this is perfectly supported and has been for a while). Afaik the > >> current > >> > > > Scala 3 version of Akka/Pekko is not using any unique/bespoke > >> features of > >> > > > Scala 3, if true this would mean from a Scala 3 user perspective > >> there > >> > > > really isn't going to be > >> > > > a difference in using a Scala 2 artifact vs Scala 3 artifact. > >> > > > > >> > > > For these reasons my recommendation would be, assuming that the > full > >> > > > release of Scala 3.3 LTS is ready by the time we decide to make a > >> release > >> > > > that we should try and target that. For details on the current > >> release > >> > > > schedule for Scala 3.3 LTS you can read > >> > > > https://contributors.scala-lang.org/t/3-3-0-release-thread/6079/3 > . > >> > > > > >> > > > -- > >> > > > > >> > > > Matthew de Detrich > >> > > > > >> > > > *Aiven Deutschland GmbH* > >> > > > > >> > > > Immanuelkirchstraße 26, 10405 Berlin > >> > > > > >> > > > Amtsgericht Charlottenburg, HRB 209739 B > >> > > > > >> > > > Geschäftsführer: Oskari Saarenmaa & Hannu Valtonen > >> > > > > >> > > > *m:* +491603708037 > >> > > > > >> > > > *w:* aiven.io *e:* matthew.dedetr...@aiven.io > >> > > > > >> > > > >> > > >> > > >> > -- > >> > > >> > Matthew de Detrich > >> > > >> > *Aiven Deutschland GmbH* > >> > > >> > Immanuelkirchstraße 26, 10405 Berlin > >> > > >> > Amtsgericht Charlottenburg, HRB 209739 B > >> > > >> > Geschäftsführer: Oskari Saarenmaa & Hannu Valtonen > >> > > >> > *m:* +491603708037 > >> > > >> > *w:* aiven.io *e:* matthew.dedetr...@aiven.io > >> > >> --------------------------------------------------------------------- > >> To unsubscribe, e-mail: dev-unsubscr...@pekko.apache.org > >> For additional commands, e-mail: dev-h...@pekko.apache.org > >> > >> > > > > -- > > > > Matthew de Detrich > > > > *Aiven Deutschland GmbH* > > > > Immanuelkirchstraße 26, 10405 Berlin > > > > Amtsgericht Charlottenburg, HRB 209739 B > > > > Geschäftsführer: Oskari Saarenmaa & Hannu Valtonen > > > > *m:* +491603708037 > > > > *w:* aiven.io *e:* matthew.dedetr...@aiven.io > > > > > -- > > Matthew de Detrich > > *Aiven Deutschland GmbH* > > Immanuelkirchstraße 26, 10405 Berlin > > Amtsgericht Charlottenburg, HRB 209739 B > > Geschäftsführer: Oskari Saarenmaa & Hannu Valtonen > > *m:* +491603708037 > > *w:* aiven.io *e:* matthew.dedetr...@aiven.io >
