^compile does not resolve internal `dependsOn` project dependency

steps

Given a project definition which includes both an sbt plugin and a non-plugin project that the sbt plugin depends on:

inThisBuild(
  Seq(
    organization := "com.example",
    version := "0.1"
  )
)

lazy val root = (project in file("."))
  .aggregate(library, plugin)
  .enablePlugins(CrossPerProjectPlugin)

val library = (project in file("library"))
  .settings(
    scalaVersion := "2.10.6",
    crossScalaVersions := Seq("2.10.6", "2.12.3")
  )

val plugin = (project in file("plugin"))
  .settings(
    sbtPlugin := true,
    crossSbtVersions := Seq("0.13.16", "1.0.0-RC3")
  )
  .dependsOn(library)

problem

When attempting to cross-compile the plugin for the given sbt versions, the following error occurs during dependency resolution:

> ^compile
[info] Setting `sbtVersion in pluginCrossBuild` to 0.13.16
[info] Set current project to plugin (in build file:/Users/jeffo/Projects/jvm/sbt-issue/)
[success] Total time: 0 s, completed Jul 31, 2017 9:58:42 AM
[info] Setting `sbtVersion in pluginCrossBuild` to 1.0.0-RC3
[info] Set current project to plugin (in build file:/Users/jeffo/Projects/jvm/sbt-issue/)
[info] Resolving com.example#library_2.12;0.1 ...
[warn] 	module not found: com.example#library_2.12;0.1
[logging elided] ...
[info] Resolving jline#jline;2.14.3 ...
[warn] 	::::::::::::::::::::::::::::::::::::::::::::::
[warn] 	::          UNRESOLVED DEPENDENCIES         ::
[warn] 	::::::::::::::::::::::::::::::::::::::::::::::
[warn] 	:: com.example#library_2.12;0.1: not found
[warn] 	::::::::::::::::::::::::::::::::::::::::::::::
[warn] 
[warn] 	Note: Unresolved dependencies path:
[warn] 		com.example:library_2.12:0.1
[warn] 		  +- com.example:plugin:0.1 (scalaVersion=2.12, sbtVersion=1.0)
[trace] Stack trace suppressed: run last plugin/*:update for the full output.
[error] (plugin/*:update) sbt.ResolveException: unresolved dependency: com.example#library_2.12;0.1: not found

expectation

I would expect that when issuing ^compile, the internal projects that my plugin depends on would be available to it without have to do a publishLocal or +publishLocal.

notes

The ^compile task succeeds if I manually issue +publishLocal from the library project before attempting ^compile.

sbt version: 0.13.16, cross building for 0.13.16 and 1.0.0-RC3

[jeffreyolchovy]

@eed3si9n I had tried that, but unfortunately I ran into another issue which forced me to reinstate the scalaVersion on the subprojects. I am still trying to track down exactly what is the cause of this other issue, but it’s something like:

- projectA is a plugin
- projectB is a plugin
- projectA and projectB both cross build for 0.13 and 1.0
- projectA and projectB do not set scalaVersion
- projectA and projectB both use scripted
- projectB depends on projectA using `dependsOn`

When running ^compile for projectB, I would get:

[warn] 	::::::::::::::::::::::::::::::::::::::::::::::
[warn] 	::          UNRESOLVED DEPENDENCIES         ::
[warn] 	::::::::::::::::::::::::::::::::::::::::::::::
[warn] 	:: org.scala-sbt#scripted-sbt_2.10;1.0.0-RC3: not found
[warn] 	::::::::::::::::::::::::::::::::::::::::::::::
[warn] 
[warn] 	Note: Unresolved dependencies path:
[warn] 		org.scala-sbt:scripted-sbt_2.10:1.0.0-RC3 ((sbt.ScriptedPlugin) ScriptedPlugin.scala#L104)
[warn] 		  +- com.example:project-a:0.1.0 (scalaVersion=2.10, sbtVersion=1.0)

The way I worked around this was not using dependsOn, but just adding a libraryDependency (and issuing publishLocal) to projectA on projectB like I did for the library and plugin dependsOn issue above.

I believe this only happens when I have the scripted dependency, so maybe I should be doing something different in my plugins.sbt when attempting to cross-build for 0.13 and 0.1. Currently, my plugins.sbt has the standard:

libraryDependencies += "org.scala-sbt" % "scripted-plugin" % sbtVersion.value

UPDATE: Seems like this other issue would be fixed by https://github.com/sbt/sbt/issues/3325

[eed3si9n]

To avoid adding scalaVersion at the project level by default, in #3356 I started appending scalaVersion at the project level only for the current subproject. In the hindsight I was walking into the situation like this whenever there’s a plugin that depends on other subprojects.

We could try issuing ++2.x.y inside ^^ command as fix.