> compile
[success]

$ copy-file changes/A2.scala src/main/scala/A.scala
[success]

> compile
[error]

$ copy-file changes/B3.scala src/main/scala/B.scala
[success]

> compile
[success]

$ delete src/main/scala/B.scala
[success]

> compile
[failure]

$ copy-file changes/B3.scala src/main/scala/B.scala
[success]

> compile
[success]

$ copy-file changes/B4.scala src/main/scala/B.scala
[success]

> compile
[failure]

$ copy-file changes/B3.scala src/main/scala/B.scala
[success]

> compile
[success]

$ copy-file changes/B5.scala src/main/scala/B.scala
[success]

> compile
[failure]

$ copy-file changes/B3.scala src/main/scala/B.scala
[success]

> compile
[success]