SBT and ScalaTest and a strange exception

After few weeks developing in Play! at some point today I started getting an Exception out of nowhere.

[info] 
Exception in thread "Thread-109" java.io.EOFException
at java.io.ObjectInputStream$BlockDataInputStream.peekByte(ObjectInputStream.java:2577)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1315)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
at sbt.React.react(ForkTests.scala:98)
at sbt.ForkTests$$anonfun$apply$2$Acceptor$2$.run(ForkTests.scala:66)
at java.lang.Thread.run(Thread.java:722)
[info] Passed: : Total 23, Failed 0, Errors 0, Passed 23, Skipped 0

Strangely enough it would be thrown on every test execution but all tests pass (see last line). 

Turns out it's a known (and already fixed) issue in sbt 0.12.2 so that was only a matter of updating:

   # sed -e 's/0.12.2/0.12.3/g' project/build.properties