specs2-commons depends on parser-combinators 2.0.0

[melezov]

Ever since 4.12.2, specs2-commons is depending on scala-parser-combinators 2.x:
https://mvnrepository.com/artifact/org.specs2/specs2-common_2.13/4.12.2

+-org.specs2:specs2-common_2.13:4.12.3 [S]
  +-org.portable-scala:portable-scala-reflect_2.13:1.1.1 [S]
  +-org.scala-lang.modules:scala-parser-combinators_2.13:2.0.0 [S]
  +-org.scala-lang:scala-reflect:2.13.6 [S]
  +-org.scala-sbt:test-interface:1.0
  +-org.specs2:specs2-fp_2.13:4.12.3 [S]

I'm raising this in light of the recent scala-xml revert to 1.3.x line in 4.12.5 as it might be something to reconsider.
Also, the code mentions that combinators 2.x are a requirement for scala-matcher-extra (https://github.com/etorreborre/specs2/blob/master/project/depends.scala#L18), but as you can see above it's being used within commons, so everywhere

scala-parser-combinators 2.x seems to be binary incompatible with 1.x as posted here:
https://github.com/scala/scala-parser-combinators/releases/tag/v2.0.0

This causes issues when adding specs2 to e.g. Play projects.
Perhaps explicitly overriding the version to either 2.x or 1.x would work in this type of setup. Will test on our CI.

[error] java.lang.RuntimeException: found version conflict(s) in library dependencies; some are suspected to be binary incompatible:
[error]
[error]         * org.scala-lang.modules:scala-parser-combinators_2.13:2.0.0 (early-semver) is selected over {1.1.2, 1.1.2, 1.1.2}
[error]             +- org.specs2:specs2-common_2.13:4.12.3               (depends on 2.0.0)
[error]             +- org.playframework.anorm:anorm_2.13:2.6.10          (depends on 1.1.2)
[error]             +- com.typesafe.play:play_2.13:2.8.8                  (depends on 1.1.2)
[error]             +- com.typesafe:ssl-config-core_2.13:0.4.2            (depends on 1.1.2)

I don't have a suggestion on how to proceed, raising for awareness.

[etorreborre]

Thanks for reporting this. I'm thinking that we should apply the same treatment as for scala-xml: leave scala-parser-combinators-1.x for specs2-4.x and scala-parser-combinators-1.x for specs2-5.x. Especially since in specs2-5.x, there's no need anymore for using scala-parser-combinators in specs2-common or specs2-core (it is now only used in specs2-matcher-extra)

[melezov]

It makes a lot of sense, since then a minor (patch) release such as 4.12.1 -> 4.12.x would not cause disruptions.
When people perform major upgrades such as 4.x -> 5.x they will pay a lot more attention to resolve dependencies correctly.

[etorreborre]

fixed now with 4.12.6

[mkurz]

Yeah, scala-parser-combinators is the same story like scala-xml, we should stay on 1.x for specs 4.12.x