Get NPE when trying to follow README instructions about tut

[tpolecat]

Well that's very strange. What version of sbt and scala are you using? Anything potentially weird in your build?

[swaldman]

I get the same NPE with tut plugin v0.4.1. The error is dependent upon whether I have

fork := true

set in build.sbt. If I don't set fork to true, the problem goes away.

When I do set fork to true, I get some extra information about the problem from the file tut is trying to generate:

For now, just a test of tut.

```scala
scala> println("Hello World!")
[init] error: error while loading Object, Missing dependency 'object scala in compiler mirror', required by /Library/Java/JavaVirtualMachines/jdk1.8.0_31.jdk/Contents/Home/jre/lib/rt.jar(java/lang/Object.class)

Failed to initialize compiler: object scala in compiler mirror not found.
** Note that as of 2.8 scala does not assume use of the java classpath.
** For the old behavior pass -usejavacp to scala, or if using a Settings
** object programatically, settings.usejavacp.value = true.

Reading around a bit, it looks like this problem might be addressed by calling a method called embedDefaults on the Settings object that is passed to the compiler. See this StackOverflow question, sbt docs and further discussion.

[tpolecat]

Ah, interesting. Thanks for tracking it down. I will check it out.

[tpolecat]

Seen also by @johnynek
https://gitter.im/tpolecat/tut?at=5924a22cfcbbe1891c3a4450

[tpolecat]

Fix is to add scala-reflect to the IMain classpath. See bazelbuild/rules_scala#202 (comment)