By the way to enable colors through jenkins you also need to specify -Djansi.force=true in mavenOpts

There seems to be a discussion already to enable colors even in batch mode: https://issues.apache.org/jira/browse/MNG-6220

I'm ok to wait and see what happens with it before we alter the pipeline-maven-plugin

Thanks dcendents for your research, I would prefer to get MNG-6220 implemented and keep the batch-mode

--batch-mode should stay. The new option is -Dstyle.color=always.

I think we all agreed batch mode should be kept and we can use the new color style property of maven once they add it. So this issue can be closed.

BTW, color style was meant to be in maven 3.5.2 but it is broken: https://issues.apache.org/jira/browse/MNG-6296)

I can confirm it works with maven 3.5.3 but it requires -Dstyle.color=always on the command line and -Djansi.force=true in the mavenOpts.

e.g. :

withMaven(mavenOpts: '-Djansi.force=true') {
    sh "mvn clean verify -Dstyle.color=always"
}

Thanks dcendents I have few questions please:

• Do you know why, in your example, `-Djansi.force=true` has to be passed in `mavenOpts` when `-Dstyle.color=true` is passed in in the args of the call?
• Do you know if passing these args to maven < 3.5.3 could introduce problems?

I don't know for sure, but assuming maven looks at system properties and not only at the CLI and that all properties passed on the CLI are added to system properties, I would say this is propbably because of the order in which the initialisation is performed.

MavenCLI -> look for style.color option on CLI only -> Jansi is initialised looks at jansi.force in system properties -> Maven adds -D CLI parameters to system properties.

As I said this is only a guess.

For your second question I'm pretty sure it is safe. I've been running a "hacked" maven 3.5.0 in jenkins (I commented the part where -B would disable colors) and I was passing -Djansi.force=true in maven properties.

As a side note for people reading this post, -Dstyle.color=always|never|auto is used by maven to decide if colors are used and then internally it uses the jansi library to render colors on the console. jansi will try to detect the type of terminal to see if colors are supported and jansi.force=true will override that check (jenkins jobs don't have a terminal that jansi recognizes).