I suffered from a bug in the setup for Scala in the last round. Although Scala code is compiled against JDK8, it is run using JDK7. I got this as a runtime error (**NOT** compile error) during the contest which puzzled me (ofcourse I did not see the error till after the contest):

java.lang.NoSuchMethodError: java.io.LineNumberReader.lines()Ljava/util/stream/Stream;
	at Scanner.<init>(_591B.scala:73)
	at Scanner.<init>(_591B.scala:66)
	at Scanner.<init>(_591B.scala:67)
	at Scanner.<init>(_591B.scala:68)
	at CodeForcesApp.main(_591B.scala:36)
	at _591B.main(_591B.scala)

Submissions: 13843944 13843313

I was able to eventually figure it out by doing a practice problem and seeing the error and resubmit and get those 2 problems correct but I lost about 45 minutes. What is the best way to report such bugs to Codeforces? Maybe we should document here (http://codeforces.me/blog/entry/79) more clearly what is done for Scala...