While I understand the motivation, such a change would break currently existing JVM build tools that work with Scala in subtle ways. More concretely it is expected that if a library is shipping the scala runtime scala-library.jar (i.e. it is a Scala library) it should use the suffix (i.e. _2.12 or _2.13) because currently existing Maven/Ivy resolution tools rely on that suffix existing when doing dependency resolution.
A simple example where this would cause a problem is if someone has a Scala project and is using Scala 2.12 and they include a future hypothetical Kafka core that only supports Scala 2.13. In the case where Kafka core preserves the 2.13 suffix, the build tool would complain that it cannot find a Kafka core release with 2.12 and tell the user immediately at resolution that Kafka has not been released with Scala 2.12 support (which is expected and the correct thing to do). On the other hand if there is no suffix, depending on the build tool in question you would essentially have to **pretend** that it's a pure Java library by ignoring the suffix (which Kafka it is not). This means that the Kafka 2.12 artifact would get incorrectly resolved in a project that is using Scala 2.13 causing a runtime error. This problem also extends transitively, i.e. think of libraries which wrap kafka clients which would transitively include kafka-core. Such a change is also incredibly misleading, I can't think of a single project using Scala that does this. There is nothing wrong with supporting only a single version of Scala and then removing Scala support later on, however the suffix in the artifact name is an expectation. I am also having trouble understanding what this is achieving when weighed against the ramifications stated earlier, if we are talking about people including specific Kafka libraries (such as kafka-clients) in their currently existing projects this is not going to provide any real benefit since current common build tools (maven/gradle/sbt) handle the suffix automatically for you during resolution. Similarly if we are talking about a distribution of Kafka that needs to be run, it's just a list of jars that need to be a classloader. On Sat, Mar 18, 2023 at 4:16 PM Ismael Juma <ism...@juma.me.uk> wrote: > Hi all, > > I would like to start a discussion regarding the removal of the scala > suffix from the kafka (aka core) module. Please take a look at the proposal > and provide feedback: > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-897%3A+Publish+a+single+kafka+%28aka+core%29+Maven+artifact+in+Apache+Kafka+4.0 > > Ismael > -- 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
