[SPARK-24573][INFRA] Runs SBT checkstyle after the build to work around a side-effect

[HyukjinKwon]

What changes were proposed in this pull request?

Seems checkstyle affects the build in the PR builder in Jenkins. I can't reproduce in my local and seems it can only be reproduced in the PR builder.

I was checking the places it goes through and this is just a speculation that checkstyle's compilation in SBT has a side effect to the assembly build.

This PR proposes to run the SBT checkstyle after the build.

How was this patch tested?

Jenkins tests.

[SparkQA]

Test build #91979 has started for PR 21579 at commit 8307cbd.

[SparkQA]

Test build #91980 has finished for PR 21579 at commit 96f5458.

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

[SparkQA]

Test build #91981 has started for PR 21579 at commit 01a9bc8.

[SparkQA]

Test build #91986 has finished for PR 21579 at commit 7f46304.

• This patch fails Java style tests.
• This patch merges cleanly.
• This patch adds no public classes.

[HyukjinKwon]

This takes 2-ish mins now given my past tries.

[HyukjinKwon]

Build / checkstyle passed in https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder/91981/console

[HyukjinKwon]

cc @cloud-fan

[SparkQA]

Test build #91988 has started for PR 21579 at commit 6529622.

[SparkQA]

Test build #91989 has started for PR 21579 at commit 73a494e.

[SparkQA]

Test build #91987 has finished for PR 21579 at commit 14351d6.

• This patch fails to generate documentation.
• This patch merges cleanly.
• This patch adds no public classes.

[HyukjinKwon]

^ I just double checked if it affects Unidoc too which we run after the build.

[viirya]

Any idea why this issue suddenly happens?

[HyukjinKwon]

One module was recently added and I was suspecting that it caused a effect from compilation by checkstyle to the build. I am not fully sure but I just suspected this by reading related places ... seems at least it fixes the issue though .. Will take it back for now actually. I think I am not fully sure why it suddenly happened.

[HyukjinKwon]

Other builds above that don't have the results were aborted intentionally. The last two build currently running are:

1. Current proposal having a Java change to make sure this PR fixes it (7eba44a).
2. Reverted the Java change by 1 (d902b10).

[SparkQA]

Test build #91997 has finished for PR 21579 at commit d902b10.

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

[HyukjinKwon]

retest this please

[SparkQA]

Test build #91995 has finished for PR 21579 at commit 7eba44a.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #91999 has finished for PR 21579 at commit d902b10.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[viirya]

ping @cloud-fan Shall we merge this to unblock the testing of other PRs?

[HyukjinKwon]

Let me merge this one. We can revert this at any moment if we see other problems and go another root, for example, clean before assembly.

[HyukjinKwon]

Or, please revert this and propose another change if anyone is clear on this. I don't mind.

Merged to master.

[HyukjinKwon]

Thanks for reviewing this @viirya and @felixcheung.

[cloud-fan]

thanks for the fix!