Regression: Ambiguous reference error

I am upgrading the community build to use the bootstrapped Dotty version and I’m hitting on an ambiguous reference error in the squants project, see https://travis-ci.org/dotty-staging/squants/builds/230324795#L561

-- [E048] Reference Error: /Users/ollie/dev/squants/shared/src/main/scala/squants/energy/Power.scala:29:24
29 |    with TimeDerivative[Energy]
   |                        ^^^^^^
   |                        reference to `Energy` is ambiguous
   |                        it is both imported by import squants._
   |                        and defined subsequently in module class energ

I had similar errors when upgrading scalatest to use the bootstrapped dotty version. Changing import squants._ to import squants.{Energy => _, _} does fix the error. However, squants.Energy is a type alias to squants.energy.Energy so I think the ambiguous reference error should not be reported. The original code compiles with dotty 20170412 as well as scalac 2.x.

I tried to find a minimal repro in https://github.com/dotty-staging/squants/pull/4/commits/d459a3b8842cdff844ff3a5ed63af45ce2c29592 but with no luck. There must be something I’m missing, help would be very much appreciated. To reproduce

git clone https://github.com/olafurpg/squants.git
cd squants
git checkout d459a3b8842cdff844ff3a5ed63af45ce2c29592
sbt squantsJVM/compile

My efforts to minimize the example are in the shared/src/main/scala/foo/ directory.

[felixmulder]

Tried to minimize this as well, but ended up crashing the compiler:

// pack.scala
package foo

package object bar {
  type Foo = foo.bar.Foo
}

// Foo.scala
package foo.bar

class Foo

// usage.scala
package boobar

import foo.bar._

object Test {
  val x: Foo = ???
}

[odersky]

Should be fixed by now. Please re-open if this is not the case.