Known Issues

The following issues were identified during release testing of this ALPHA release but have not been deemed as release blockers:

• MNG-6177 The --file and -f option to specify a pom.xml to use does not work if the path includes characters that need quoting such as whitespace or &.
• MNG-6115 If Maven is installed in a writable location, every build will create a new lib/ext/jansi-.... file.

Why not Maven 3.4.0?

After Maven 3.3.9 was released, the Eclipse Aether project was retired and the code base was migrated to the Apache Maven project.

The original goal for the 3.4.0 release was to replace Aether with the exact same code after migration to the Apache Maven project and then proceed with bug fixes to the resolver code as well as other areas of Maven.

The migration of the code between the two foundations took longer than expected and as a result there were other changes committed to Maven core that were outside the scope of intent for 3.4.0.

In order to refocus on the original intent for 3.4.0, the decision was taken to revert the Maven core history to the point of the 3.3.9 release and merge in the desired changes one at a time.

Because there had been a lot of communication about different features being delivered and bugs fixed in Maven 3.4.0 and the new history may not contain them in the first release, the decision was taken to forever burn the 3.4.x release line.

More detail on this decision can be read in the mailing list archive.

Reporters and Contributors of this release

Bugs:

• MNG-5963 reporter: Larry Singer
• MNG-5962 reporter/contributor: Miriam Lee
• MNG-5961 reporter: Mike Drob
• MNG-5958 reporter: Meytal Genah, contributor: Anton Tanasenko
• MNG-5852 reporter: Jeffrey Alexander
• MNG-5823 reporter: Tobias Oberlies
• MNG-5815 reporter: Peter Kjær Guldbæk
• MNG-5368 reporter: Andrew Haines

Improvements:

• MNG-6030 reporter: Andriy contributor: Andriy
• MNG-5934 reporter/contributor: Alex Henrie
• MNG-5883 reporter: Ben Caradoc-Davies
• MNG-3507 contributors: Jason Dillon, Sébastian Le Merdy

Many thanks to all reporters and contributors for their time and support.

Preliminary Testers

Thank you also for your time and feedback.

Overview about the changes

• The most obvious change you may encounter is that the console output has colors now MNG-3507, MNG-6093.

• The new project.directory special property adds support in every calculated URLs (project, SCM, site) for module directory name that does not match artifactId MNG-5878

• The JAVA_HOME discovery has been reduced to simply check if JAVA_HOME is set or not then trying to discover via which java, nothing more MNG-6003.

• The build bootstrapping support via Apache Ant has been removed. You can now only bootstrap Maven build with a previous version of Maven, but not with Ant any more MNG-5904.

• Based on problems in using M2_HOME related to different Maven versions installed and to simplify things, the usage of M2_HOME has been removed and is not supported any more MNG-5823, MNG-5836, MNG-5607.

• Important change for windows users: The usage of %HOME% has been replaced with %USERPROFILE% MNG-6001

• Several issues have been reported and fixed related to the mvn script either for Unix/Linux/Cygwin/Solaris or for Windows MNG-5815, MNG-5852, MNG-5963, MNG-6022.

• In Maven 3.3.9, we have removed bindings for maven-ejb3-plugin because it does not exist. We follow-up and removed the artifact handler for ejb3 and the par lifecycle MNG-6014, MNG-6017.

• In previous Maven versions, there had been a larger problem related to memory usage in case of very large reactors (200-300 modules or more) which caused failures with out of memeory exceptions or the need to increase the memory settings. This problem has been fixed with MNG-6030.

• If you have defined a property within the .mvn/maven.config file, it was not possible to overwrite the property via command line. This has been fixed with MNG-6078.

• If you have are using <prerequisites>..</prerequisites> for a non maven-plugin project, you will get a WARNING which looks like this:

[INFO] Scanning for projects...
[WARNING] The project org.apache.maven:maven:pom:3.5.0-SNAPSHOT uses prerequisites which is only intended for maven-plugin projects but not for non maven-plugin projects. For such purposes you should use the maven-enforcer-plugin. See https://maven.apache.org/enforcer/enforcer-rules/requireMavenVersion.html

This will tell you to use maven-enforcer-plugin to check the version of Maven you are expecting to build your project with, instead of using prerequisites MNG-5297, MNG-6092.

• Replaced Eclipse Aether with Maven Resolver MNG-6110, MNG-6140.

Improvements:

Bugs:

• MNG-5297 - Site should tell ‘prerequisites.maven is deprecated’
• MNG-5368 - UnsupportedOperationException thrown when version range is not correct in dependencyManagement definitions
• MNG-5629 - ClosedChannelException from DefaultUpdateCheckManager.read
• MNG-5815 - “mvn.cmd” does not indicate failure properly when using “&&”
• MNG-5823 - mvnDebug doesn't work with M2_HOME with spaces - missing quotes
• MNG-5829 - mvn shell script fails with syntax error on Solaris 10
• MNG-5836 - logging config is overridden by $M2_HOME/lib/ext/*.jar
• MNG-5852 - mvn shell script invokes /bin/sh but requires Bash functions
• MNG-5958 - java.lang.String cannot be cast to org.apache.maven.lifecycle.mapping.LifecyclePhase
• MNG-5961 - Maven possibly not aware of log4j2
• MNG-5962 - mvn.cmd fails when the current directory has spaces in between
• MNG-5963 - mvn.cmd does not return ERROR_CODE
• MNG-6022 - mvn.cmd fails if directory contains an ampersand (&)
• MNG-6053 - Unsafe System Properties copy in MavenRepositorySystemUtils, causing NPEs
• MNG-6105 - properties.internal.SystemProperties.addSystemProperties() is not really thread-safe
• MNG-6109 - PluginDescriptor doesn't read since value of parameter
• MNG-6117 - ${session.parallel} not correctly set
• MNG-6144 - DefaultWagonManagerTest#testGetMissingJarForced() passed incorrect value
• MNG-6166 - mvn dependency:go-offline fails due to missing transitive dependency jdom:jdom:jar:1.1
• MNG-6171 - REGRESSION: WARNING about usage of a non threadsafe marked plugin is not showed anymore
• MNG-6172 - Precedence of command-line system property options has changed

Dependency upgrade:

• MNG-5967 - Dependency updates
• MNG-6110 - Upgrade Aether to Maven Resolver

Improvements:

• MNG-5579 - Unify error output/check logic from shell and batch scripts
• MNG-5607 - Don't use M2_HOME in mvn shell/command scripts anymore
• MNG-5883 - Silence unnecessary legacy local repository warning
• MNG-5889 - .mvn directory should be picked when using –file
• MNG-5904 - Remove the whole Ant build
• MNG-5931 - Fixing documentation
• MNG-5934 - String handling issues identified by PMD
• MNG-5946 - Fix links etc. in README.txt which is part of the delivery
• MNG-5968 - Default plugin version updates
• MNG-5975 - Use Java 7's SimpleDateFormat in CLIReportingUtils#formatTimestamp
• MNG-5977 - Improve output readability of our MavenTransferListener implementations
• MNG-5993 - Confusing error message in case of missing/empty artifactId and version in pluginManagement
• MNG-6001 - Replace %HOME% with %USERPROFILE% in mvn.cmd
• MNG-6003 - Drastically reduce JAVA_HOME discovery code
• MNG-6014 - Removing ArtifactHandler for ejb3
• MNG-6017 - Removing ArtifactHandler for par LifeCycle
• MNG-6030 - ReactorModelCache do not used effectively after maven version 3.0.5 which cause a large memory footprint
• MNG-6032 - WARNING during build based on absolute path in assembly-descriptor.
• MNG-6068 - Document default scope compile in pom XSD and reference documentation
• MNG-6078 - Can't overwrite properties which have been defined in .mvn/maven.config
• MNG-6081 - Log refactoring - Method Invocation Replaced By Variable
• MNG-6102 - Introduce ${maven.conf} in m2.conf
• MNG-6145 - Remove non-existent m2 include in component.xml
• MNG-6146 - Several small stylistic and spelling improvements to code and documentation
• MNG-6147 - MetadataResolutionResult#getGraph() contains duplicate if clause
• MNG-6150 - Javadoc improvements for 3.5.0
• MNG-6163 - Introduce CLASSWORLDS_JAR in shell startup scripts
• MNG-6165 - Deprecate and replace incorrectly spelled public API

New Feature:

• MNG-3507 - ANSI color logging for improved output visibility
• MNG-5878 - add support for module name != artifactId in every calculated URLs (project, SCM, site): special project.directory property
• MNG-6093 - create a slf4j-simple provider extension that supports level color rendering Task
• MNG-5954 - Remove outdated maven-embedder/src/main/resources/META-INF/MANIFEST.MF
• MNG-6106 - Remove maven.home default value setter from m2.conf
• MNG-6136 - Upgrade Maven Wagon from 2.10 to 2.12
• MNG-6137 - Clean up duplicate dependencies caused by incomplete Wagon HTTP Provider exclusions
• MNG-6138 - Remove obsolete message_*.properties form maven-core
• MNG-6140 - update documentation's dependency graph with resolver + resolver-provider + slf4j-provider
• MNG-6151 - Force Push master from 737de43e392fc15a0ce366db98d70aa18b3f6c03
• MNG-6152 - Add a Jenkinsfile so that builds.apache.org can use multibranch pipeline

Wishes:

• MNG-2199 - Support version ranges in parent elements
• MNG-6088 - after forked execution success, add an empty line
• MNG-6092 - warn if prerequisites.maven is used for non-plugin projects

The full list of changes can be found in our issue management system.

Complete Release Notes

See complete release notes for all versions