Test branch to see how Scala 2.11.12 performs

[RussellSpitzer]

This may be useful when Java 8 is no longer supported since
Scala 2.11.12 supports later versions of Java

What changes were proposed in this pull request?

Change Scala Build Version to 2.11.12.

How was this patch tested?

This PR is made to run 2.11.12 Scala through Jenkins to see whether or not it passes cleanly.

Please review http://spark.apache.org/contributing.html before opening a pull request.

[dbtsai]

I'm also looking at this issue. The challenge is that one of the hacks we use to initialize the Spark
before REPL sees any files was removed in Scala 2.11.12.

https://github.com/apache/spark/blob/master/repl/scala-2.11/src/main/scala/org/apache/spark/repl/SparkILoop.scala#L109

We might need to work with Scala team to upgrade our Scala version.

[dbtsai]

Here is the issue in Scala side. scala/bug#10913

[rxin]

Jenkins, test this please.

[rxin]

Jenkins, add to whitelist.

[HyukjinKwon]

Jenkins, test this please

[HyukjinKwon]

Jenkins, add to whitelist

[SparkQA]

Test build #91322 has finished for PR 21453 at commit 90d3842.

• This patch fails build dependency tests.
• This patch merges cleanly.
• This patch adds no public classes.

[jerryshao]

Scala 2.11.12 cannot be built against with current Spark, due to some method changes in REPL. We have tried internally.

[dbtsai]

I filed an issue in Scala community about the interface changes, and they said those REPL apis are intended to be private. scala/bug#10913

Being said that, they gave us couple ways to walk around it, and I'm testing it now.

[dbtsai]

I opened a PR for Scala 2.11.12 with potential Scala API change fix. #21495 Thanks.

[jerryshao]

I think we can close this one as a dup of #21495 .

[SparkQA]

Test build #92866 has finished for PR 21453 at commit 90d3842.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.