Download and unpack Eclipse latest SDK build from http://download.eclipse.org/eclipse/downloads/ . The instructions below assume fresh/clean Eclipse installation.
Install M2Eclipse 1.7 or newer from http://download.eclipse.org/technology/m2e/releases . This is a P2 repository URL, use Eclipse Install UI to use it as explained in http://help.eclipse.org/topic/org.eclipse.platform.doc.user/tasks/tasks-127.htm
Clone the M2Eclipse Core repository, see https://git.eclipse.org/r/#/admin/projects/m2e/m2e-core for the list of available protocols.
Clone M2Eclipse Tests repository, see https://github.com/tesla/m2e-core-tests for the list of available protocols.
Import org.eclipse.m2e.workspace, m2e-core and m2e-core-tests as existing maven projects. Follow onscreen instructions, allow M2Eclipse to install additional software and restart eclipse when requested. Give Eclipse some time to update project configuration after restart. You may need to do Project/Clean…/Clean_all_projects to clear all compilation errors.
Add the following memory configuration parameters to JVM startup options
Use JUnit Plug-in Tests launch configuration type to run/debug M2Eclipse automated regressions tests from Eclipse.
Caveat. Two tests are expected to fail when run from Eclipse
ProjectRegistryManagerTest#testEnvironmentVariablesConsidered requires TEMP environment variable to be set and is expected to failed when run from Eclipse.
MarkerTest#test is rather sloppy and requires elaborate launch configuration setup to limit set of m2e extensions enabled during the test.
Both tests are expected to pass on command line (see instructions below).
Building m2e on command line is a two step process, both performed from root of m2e-core checkout directory
First, you need to install m2e maven runtime to local maven repository
mvn clean install -f m2e-maven-runtime/pom.xml`
Then, package M2Eclipse update site:
mvn clean package
The repository is created under org.eclipse.m2e.site/target/repository directory.
To run m2e automated regression tests, execute the following command from m2e-core-tests checkout directory
mvn clean integration-test -Puts,its -fae -Dm2e-core.url=file://<full-path-to-m2e-repository>
M2Eclipse only accepts changes contributed via Gerrit. Here is the wiki that explains how to use it http://wiki.eclipse.org/Gerrit . Good luck.
According to eclipse legal poster, all contributors must have signed Eclipse CLA and their bugzilla email and git commit author must match (otherwise Eclipse git server refuses contribution).
Note that M2Eclipse developers do NOT watch Gerrit submissions directly. All contributions must be referenced from corresponding bugzilla records.
In most cases m2e core patches will require corresponding regression tests. Changes to m2e core tests repository must be submitted as github pull requests and must be linked to bugzilla record, along with corresponding Gerrit change set.