Maven can't locate this plugin due to "org.apache.maven.plugin.prefix.NoPluginFoundForPrefixException: No plugin found for prefix 'spotless'"

[matts19]

When try to run "mvn -s settings.xml spotless:check", it can't locate this plugin due to "org.apache.maven.plugin.prefix.NoPluginFoundForPrefixException: No plugin found for prefix 'spotless'"

I even entered the plugin group info in settings.xml:
<pluginGroups>
  <pluginGroup>com.diffplug.spotless</pluginGroup>
</pluginGroups>

But maven refuses to find this plugin via prefix. Full naming works though (com.diffplug.spotless:spotless-maven-plugin:check).

For the prefix to work my understanding is that the plugin should provide prefix info in its maven-metadata.xml at the group level. But this plugin does not come with such meta data file. It only has maven-metadata.xml at the artifact level for each artifact version. That is, I could not find maven-metadata.xml which content like this:

<metadata>
  <plugins>
    <plugin>
      <name>Some Awesome Maven Plugin</name>
      <prefix>somePrefix</prefix>
      <artifactId>some-maven-plugin</artifactId>
    </plugin>
  </plugins>
</metadata>

- [ ] gradle or maven version

Maven 3.5.0

- [ ] spotless version

1.27.0 but I tried many other versions

- [ ] operating system and version

Ubuntu Xenial

- [ ] copy-paste your full Spotless configuration block(s), and a link to a public git repo that reproduces the problem if possible

It's very simple.

<plugin>
    <groupId>com.diffplug.spotless</groupId>
    <artifactId>spotless-maven-plugin</artifactId>
    <version>1.21.0</version>
    <configuration>
        <java>
            <removeUnusedImports/>
        </java>
    </configuration>
</plugin>

- [ ] copy-paste the full content of any console errors 

[DEBUG] Resolving plugin prefix spotless from [com.diffplug.spotless, org.apache.maven.plugins, org.codehaus.mojo]
[DEBUG] Using mirror repo (http://scctools.dt.vmware.com:8081/artifactory/repo) for plexus-snapshots (https://oss.sonatype.org/content/repositories/plexus-snapshots).
[DEBUG] Using mirror repo (http://scctools.dt.vmware.com:8081/artifactory/repo) for apache.snapshots (http://repository.apache.org/snapshots).
[DEBUG] Using mirror repo (http://scctools.dt.vmware.com:8081/artifactory/repo) for codehaus.org (http://snapshots.repository.codehaus.org).
[DEBUG] Could not find metadata com.diffplug.spotless/maven-metadata.xml in local (/home/jenkins/.m2/repository)
[DEBUG] Could not find metadata org.apache.maven.plugins/maven-metadata.xml in local (/home/jenkins/.m2/repository)
[DEBUG] Could not find metadata org.codehaus.mojo/maven-metadata.xml in local (/home/jenkins/.m2/repository)
[DEBUG] Using transporter WagonTransporter with priority -1.0 for http://scctools.dt.vmware.com:8081/artifactory/repo
[DEBUG] Using transporter WagonTransporter with priority -1.0 for http://scctools.dt.vmware.com:8081/artifactory/repo
[DEBUG] Using transporter WagonTransporter with priority -1.0 for http://scctools.dt.vmware.com:8081/artifactory/repo
[DEBUG] Using connector BasicRepositoryConnector with priority 0.0 for http://scctools.dt.vmware.com:8081/artifactory/repo
[DEBUG] Using connector BasicRepositoryConnector with priority 0.0 for http://scctools.dt.vmware.com:8081/artifactory/repo
[DEBUG] Using connector BasicRepositoryConnector with priority 0.0 for http://scctools.dt.vmware.com:8081/artifactory/repo
Downloading: http://scctools.dt.vmware.com:8081/artifactory/repo/org/apache/maven/plugins/maven-metadata.xml
Downloading: http://scctools.dt.vmware.com:8081/artifactory/repo/org/codehaus/mojo/maven-metadata.xml
Downloading: http://scctools.dt.vmware.com:8081/artifactory/repo/com/diffplug/spotless/maven-metadata.xml
[DEBUG] Writing tracking file /home/jenkins/.m2/repository/com/diffplug/spotless/resolver-status.properties

<snipped....>

[DEBUG] Could not find metadata com.diffplug.spotless/maven-metadata.xml in repo (http://scctools.dt.vmware.com:8081/artifactory/repo)
[DEBUG] Could not find metadata com.diffplug.spotless/maven-metadata.xml in local (/home/jenkins/.m2/repository)
[DEBUG] Skipped remote request for com.diffplug.spotless/maven-metadata.xml, already updated during this session.
[DEBUG] Failure to find com.diffplug.spotless/maven-metadata.xml in http://scctools.dt.vmware.com:8081/artifactory/repo was cached in the local repository, resolution will not be reattempted until the update interval of repo has elapsed or updates are forced
[DEBUG] Could not find metadata org.apache.maven.plugins/maven-metadata.xml in local (/home/jenkins/.m2/repository)
[DEBUG] Could not find metadata org.codehaus.mojo/maven-metadata.xml in local (/home/jenkins/.m2/repository)

[Shanky2304]

I have the same issue. It'll be much more handy if people can use the shorter version for this plugin otherwise it will just fizzle out as one of those "recommendations"

[nedtwigg]

This might be a dumb question, but I'm not great with maven. At the very top of our plugin-maven readme, we've got a little plugin block to copy, and it looks like you copied it exactly right. We also have an example command line mvn spotless:check. I do a little integration testing for each release to confirm that it is still working, and it is, for me.

I don't understand how having a <pluginGroups> in your settings.xml comes into it at all. I read these maven docs which reference it, but I still don't get it.

Regardless of whether I understand the problem or not, we're happy to take a PR to fix/improve it. Here is our POM template:

https://github.com/diffplug/spotless/blob/e870e78999887595d8480c699c4ef71c9e974b32/plugin-maven/src/test/resources/pom-build.xml.mustache

And here is how we populate and run it:

spotless/plugin-maven/build.gradle

Lines 139 to 180 in e870e78

	task createPomXml(dependsOn: installLocalDependencies) {
	doLast {
	def additionalDependencies = project.configurations.runtimeClasspath.resolvedConfiguration.resolvedArtifacts.findAll {
	return !libs.contains(it.moduleVersion.id.name)
	}.collect {
	return " <dependency>\n" +
	" <groupId>${it.moduleVersion.id.group}</groupId>\n" +
	" <artifactId>${it.moduleVersion.id.name}</artifactId>\n" +
	" <version>${it.moduleVersion.id.version}</version>\n" +
	" </dependency>\n"
	}.join()
	def versions = [
	spotlessMavenPluginVersion: version,
	mavenApiVersion : VER_MAVEN_API,
	eclipseAetherVersion : VER_ECLIPSE_AETHER,
	spotlessLibVersion : libVersion,
	additionalDependencies : additionalDependencies
	]
	def pomXmlTemplate = Paths.get(PROJECT_DIR, "src/test/resources/pom-build.xml.mustache")
	def newPomXml = Paths.get(MAVEN_PROJECT_DIR, "pom.xml")
	Files.newBufferedReader(pomXmlTemplate).withCloseable { reader ->
	Files.newBufferedWriter(newPomXml, UTF_8, CREATE_NEW, TRUNCATE_EXISTING).withCloseable { writer ->
	def mustache = new DefaultMustacheFactory().compile(reader, "pom")
	mustache.execute(writer, versions)
	}
	}
	}
	}
	task runMavenBuild(type: Exec, dependsOn: [
	cleanMavenProjectDir,
	copySourceFiles,
	copyMvnw,
	createPomXml
	]) {
	workingDir MAVEN_PROJECT_DIR
	// -B batch mode to make dependency download logging less verbose
	commandLine mvnw("clean install -B -Dmaven.repo.local=${LOCAL_MAVEN_REPO_DIR}")
	}

I'm happy to help with any gradle integration issues, but I don't know anything about the maven part.

[nedtwigg]

Closing due to inactivity and inability to replicate. Happy to reopen with an open source repo that demonstrates the issue.

[vlaw]

I have the same issue.

$ mvn -X spotless:check
...
[DEBUG] Could not find metadata com.diffplug.spotless/maven-metadata.xml in central (https://repo.maven.apache.org/maven2)
......
......
[ERROR] No plugin found for prefix 'spotless' in the current project and in the plugin groups [com.diffplug.spotless, com.github.spotbugs, org.apache.maven.plugins, org.codehaus.mojo] available from the repositories [local (/Users/luowentao/.m2/repository), central (https://repo.maven.apache.org/maven2)] -> [Help 1]

I'm not familiar with building a maven plugin neither. But I do find something, I guess.
There is NO maven-metadata.xml under https://repo.maven.apache.org/maven2/com/diffplug/spotless/.

As a contrast, there are two other pluginGroups , which have maven-metadata.xml in centra repo.

• https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-metadata.xml
• https://repo.maven.apache.org/maven2/com/github/spotbugs/maven-metadata.xml

<metadata>
<plugins>
  <plugin>
    <name>SpotBugs Maven Plugin</name>
    <prefix>spotbugs</prefix>      <!-- HERE -->
    <artifactId>spotbugs-maven-plugin</artifactId>
  </plugin>
</plugins>
</metadata>

So, maybe there is something go wrong during DEPLOY phrase, or maybe maven-publish error?
I'm not quit sure, hope this will give some clue.

[glucazeau]

👋 It is unfortunately still an issue.

As @vlaw said the repository is missing maven-metadata file (another example for sonar:sonar plugin : maven-metadata.xml)

According to the documentation, this file at group level should be automatically uploaded when using "maven-plugin" as packaging type.
I couldn't find where and if this packaging type is specified somewhere in the Gradle build configuration of the plugin.

Furthermore, it says here that the Gradle "maven-publish" plugin seems to ignore the packaging type.
I don't know if it's still the case, but I would suppose that this plugin is used for traditional Maven projects, and that most of the Maven plugins are built and published with Maven itself.

I hope this can help, it would be really nice to be able to simply call mvn spotless:check (on a global GitHub workflow for instance)

[a-t-0]

For anyone searching to resolve the same No plugin found for prefix 'spotless' error, here is a solution (that uses Maven).