`%%%` seems broken with "illegal dynamic reference"

[sjrd]

The following causes an "illegal dynamic reference: autoImport" error to be reported by sbt:

libraryDependencies += "org.scala-js" %%% "scalajs-dom" % "0.7.0-SNAPSHOT"

If I inline the body of the %%% macro, everything works fine:

libraryDependencies += {
  import org.scalajs.sbtplugin._
  val cross = {
    if (ScalaJSPlugin.autoImport.jsDependencies.?.value.isDefined)
      ScalaJSCrossVersion.binary
    else
      CrossVersion.binary
  }
  impl.ScalaJSGroupID.withCross("org.scala-js", "scalajs-dom", cross) % "0.7.0-SNAPSHOT"
}

[sjrd]

Workaround: use %%%! instead if your settings are actually JS-only.
For shared settings, use the manually expanded version above.

[lihaoyi]

Should we make %%% the JS-only one and %%%! the magic macro-one? I imagine that most cases would want to be JS-only, and the macro cross-build thing is more an advanced feature. Just a thought, since the macro-stuff has other edge cases other than this (e.g. can't just put them in a list without a += or ++= first) that will probably confuse people.

[gzm0]

Probably our "Hack to work around bug in sbt macros" does not work anymore. I'll start bisecting to better understand the problem.

[gzm0]

Bisect says its: c22d418 (Turn sbt plugin into auto plugin). This is really strange. I would have expected this to be a break caused by an sbt upgrade.

[sjrd]

Actually I was expecting that one ^^
Maybe try to symbol-Ident the ScalaJSPlugin object separately, then select the AutoImport field from within the reify?

[gzm0]

Doesn't work... I already tried a couple of combinations. Its strange, since the structure (in terms of scala) has not changed at all. Before we had ScalaJSPlugin.ScalaJSKeys.jsDependencies, now we have ScalaJSPlugin.autoImport.jsDependencies.

There is no structural difference except that autoImport extends something... (and is lower case, but I really hope its not that one...)

[gzm0]

It seems that if I do this:

val autoImport = AutoImport

object AutoImport {
  // etc.
}

It works. I still need to verify this, since it is... incredible.