如何克服“可能存在不兼容性...” SBT警告？

Question

我是SBT的新手，不确定执行该evicted任务中的一个相当可怕的警告该怎么做： [warn] There may be incompatibilities among your library dependencies; run 'evicted' to see detailed eviction warnings.

完整的任务输出为...

sbt:Sprout> evicted
[info] Updating ...
[info] Done updating.
[warn] There may be incompatibilities among your library dependencies; run 'evicted' to see detailed eviction warnings.
[warn] Found version conflict(s) in library dependencies; some are suspected to be binary incompatible:
[warn]  * org.scala-lang.modules:scala-xml_2.12:1.1.0 is selected over 1.0.6
[warn]      +- org.json4s:json4s-xml_2.12:3.6.3                   (depends on 1.1.0)
[warn]      +- org.scalatra:scalatra_2.12:2.6.5                   (depends on 1.0.6)
[warn]      +- com.typesafe.play:twirl-api_2.12:1.3.13            (depends on 1.0.6)
[info] Here are other dependency conflicts that were resolved:
[info]  * org.json4s:json4s-core_2.12:3.6.5 is selected over 3.6.3
[info]      +- org.json4s:json4s-jackson_2.12:3.6.5               (depends on 3.6.5)
[info]      +- org.json4s:json4s-xml_2.12:3.6.3                   (depends on 3.6.3)
[info]      +- org.scalatra:scalatra-json_2.12:2.6.5              (depends on 3.6.3)
[info]  * org.json4s:json4s-scalap_2.12:3.6.5 is selected over 3.6.3
[info]      +- org.json4s:json4s-core_2.12:3.6.5                  (depends on 3.6.5)
[info]      +- org.json4s:json4s-core_2.12:3.6.3                  (depends on 3.6.3)
[info]  * org.json4s:json4s-ast_2.12:3.6.5 is selected over 3.6.3
[info]      +- org.json4s:json4s-core_2.12:3.6.5                  (depends on 3.6.5)
[info]      +- org.json4s:json4s-core_2.12:3.6.3                  (depends on 3.6.3)
[success] Total time: 1 s, completed Apr 13, 2019 12:53:54 PM

“怀疑二进制不兼容”听起来很严重。是吗？

是否只有一些排除项可以标记依赖项，以使依赖项符合正确版本的要求？

SBT依赖项就像...

libraryDependencies ++= Seq(
  "org.scalatra" %% "scalatra" % ScalatraVersion exclude("org.slf4j","slf4j-api"),
  "org.scalatra" %% "scalatra-scalatest" % ScalatraVersion % "test",
  "org.slf4j" % "slf4j-api" % "1.7.26",
  "ch.qos.logback" % "logback-classic" % "1.2.3" % "runtime",
  "org.eclipse.jetty" % "jetty-webapp" % "9.4.9.v20180320" % "container",
  "javax.servlet" % "javax.servlet-api" % "3.1.0" % "provided",
  "org.scalatra" %% "scalatra-json" % ScalatraVersion,
  "org.json4s"   %% "json4s-jackson" % "3.6.5",
)

Answer 1

出现此警告是因为org.scalatra:scalatra_2.12:2.6.5＆com.typesafe.play:twirl-api_2.12:1.3.13取决于org.scala-lang.modules:scala-xml_2.12:1.0.6，但是org.json4s:json4s-xml_2.12:3.6.3使用org.scala-lang.modules:scala-xml_2.12:1.1.0

为了隐藏此警告，您可以使用dependencyOverrides：

dependencyOverrides += "org.scala-lang.modules" % "scala-xml_2.12" % "1.0.6"

同样，它只会隐藏警告，但不能保证库与您设置的版本之间具有兼容性。

Answer 2

理想情况下，如果可能的话，由于可能引入难以追踪的错误，我们应该解决驱逐警告而不是覆盖。在这种情况下，如果我们愿意分别删除scalatra和json4s-jackson版本到2.6.4和是可能的3.5.2，如下所示：

val ScalatraVersion = "2.6.4"

libraryDependencies ++= Seq(
  "org.scalatra" %% "scalatra" % ScalatraVersion exclude("org.slf4j","slf4j-api"),
  "org.scalatra" %% "scalatra-scalatest" % ScalatraVersion % "test",
  "org.slf4j" % "slf4j-api" % "1.7.26",
  "ch.qos.logback" % "logback-classic" % "1.2.3" % "runtime",
  "javax.servlet" % "javax.servlet-api" % "3.1.0" % "provided",
  "org.scalatra" %% "scalatra-json" % ScalatraVersion,
  "org.json4s"   %% "json4s-jackson" % "3.5.2",
)