"Runtime references to undefined settings" error when use sbt.ProjectRef

[xuwei-k]

• https://github.com/xuwei-k/neo-scalafmt-ProjectRef-error/commit/d8cdbfba3f55bb03df1dc1bf454f6088390fbb32
• https://travis-ci.org/xuwei-k/neo-scalafmt-ProjectRef-error/builds/317218379

a/build.sbt

val b = project

build.sbt

val b = ProjectRef(file("a"), "b")

val c = project.dependsOn(b)

project/build.properties

sbt.version=0.13.16

project/plugin.sbt

addSbtPlugin("com.lucidchart" % "sbt-scalafmt" % "1.14")

error log

Runtime references to undefined settings: 
  {file:/home/travis/build/xuwei-k/neo-scalafmt-ProjectRef-error/a/}a/sbt:scalafmtOnCompile from */*:onLoad ((com.lucidchart.sbt.scalafmt.ScalafmtSbtPlugin) ScalafmtSbtPlugin.scala:16)
  {file:/home/travis/build/xuwei-k/neo-scalafmt-ProjectRef-error/a/}b/sbt:scalafmtOnCompile from */*:onLoad ((com.lucidchart.sbt.scalafmt.ScalafmtSbtPlugin) ScalafmtSbtPlugin.scala:16)
 
	at sbt.Init$class.Uninitialized(Settings.scala:270)
	at sbt.Def$.Uninitialized(Def.scala:10)
	at sbt.Init$class.make(Settings.scala:148)
	at sbt.Def$.make(Def.scala:10)
	at sbt.Load$$anonfun$8.apply(Load.scala:161)
	at sbt.Load$$anonfun$8.apply(Load.scala:156)
	at sbt.Load$.timed(Load.scala:1025)
	at sbt.Load$.apply(Load.scala:156)
	at sbt.Load$.defaultLoad(Load.scala:39)
	at sbt.BuiltinCommands$.liftedTree1$1(Main.scala:503)
	at sbt.BuiltinCommands$.doLoadProject(Main.scala:503)
	at sbt.BuiltinCommands$$anonfun$loadProjectImpl$2.apply(Main.scala:495)
	at sbt.BuiltinCommands$$anonfun$loadProjectImpl$2.apply(Main.scala:495)
	at sbt.Command$$anonfun$applyEffect$1$$anonfun$apply$2.apply(Command.scala:59)
	at sbt.Command$$anonfun$applyEffect$1$$anonfun$apply$2.apply(Command.scala:59)
	at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:61)
	at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:61)
	at sbt.Command$.process(Command.scala:93)
	at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:96)
	at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:96)
	at sbt.State$$anon$1.runCmd$1(State.scala:183)
	at sbt.State$$anon$1.process(State.scala:187)
	at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:96)
	at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:96)
	at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)
	at sbt.MainLoop$.next(MainLoop.scala:96)
	at sbt.MainLoop$.run(MainLoop.scala:89)
	at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:68)
	at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:63)
	at sbt.Using.apply(Using.scala:24)
	at sbt.MainLoop$.runWithNewLog(MainLoop.scala:63)
	at sbt.MainLoop$.runAndClearLast(MainLoop.scala:46)
	at sbt.MainLoop$.runLoggedLoop(MainLoop.scala:30)
	at sbt.MainLoop$.runLogged(MainLoop.scala:22)
	at sbt.StandardMain$.runManaged(Main.scala:61)
	at sbt.xMain.run(Main.scala:35)
	at xsbt.boot.Launch$$anonfun$run$1.apply(Launch.scala:109)
	at xsbt.boot.Launch$.withContextLoader(Launch.scala:128)
	at xsbt.boot.Launch$.run(Launch.scala:109)
	at xsbt.boot.Launch$$anonfun$apply$1.apply(Launch.scala:35)
	at xsbt.boot.Launch$.launch(Launch.scala:117)
	at xsbt.boot.Launch$.apply(Launch.scala:18)
	at xsbt.boot.Boot$.runImpl(Boot.scala:41)
	at xsbt.boot.Boot$.main(Boot.scala:17)
	at xsbt.boot.Boot.main(Boot.scala)
[error] Runtime references to undefined settings: 
[error] 
[error]   {file:/home/travis/build/xuwei-k/neo-scalafmt-ProjectRef-error/a/}a/sbt:scalafmtOnCompile from */*:onLoad ((com.lucidchart.sbt.scalafmt.ScalafmtSbtPlugin) ScalafmtSbtPlugin.scala:16)
[error] 
[error]   {file:/home/travis/build/xuwei-k/neo-scalafmt-ProjectRef-error/a/}b/sbt:scalafmtOnCompile from */*:onLoad ((com.lucidchart.sbt.scalafmt.ScalafmtSbtPlugin) ScalafmtSbtPlugin.scala:16)
[error]  
[error] Use 'last' for the full log.
Project loading failed: (r)etry, (q)uit, (l)ast, or (i)gnore?