Download and unpack Eclipse latest SDK build from http://download.eclipse.org/eclipse/downloads/. The instructions below assume fresh/clean Eclipse SDK installation.
Use the instructions at http://help.eclipse.org/topic/org.eclipse.platform.doc.user/tasks/tasks-124.htm to install “Maven integration for Eclipse” and “Git integration for Eclipse” from the standard update sites of the Eclipse SDK. You can also find and install the most recent release of these plugins in the following P2 repository URLs, which can be added using the Eclipse Install UI as explained in http://help.eclipse.org/topic/org.eclipse.platform.doc.user/tasks/tasks-127.htm:
Some modules of the m2e core code make use of logback classic. When you later proceed to import projects, you will get errors in some (e.g. org.eclipse.m2e.logback.appender and org.eclipse.m2e.logback.configuration) complaining that you are missing the ch.qos.logback.classic library in your Eclipse. The easiest way to install the “Logback Classic Module” is to again use the instructions at http://help.eclipse.org/topic/org.eclipse.platform.doc.user/tasks/tasks-124.htm to install the “m2e - slf4j over logback logging” optional plugin. This provides a maven console in your host workspace. Alternatively if you do not want that feature, you need to at least inestall the “Logback Classic Module” plugin from the Orbit repository, so that it is available in your host Eclipse.
You should now have all plugins you need in your Eclipse to proceed with building the source code.
The code is split across two repositories:
The latter is configured as a git submodule of the former. Either clone the first repository including submodules, or just clone both repositories separately. Either way, before proceeding to import anything into you workspace, make sure you are on the matching branches of the m2e-core repository and the m2e-core-tests repository (whether that was cloned separately or as a submodule). For example if you are on the master branch of m2e-core you should be on the master branch of m2e-core-tests as well. Otherwise you may get errors when oou import from the latter, where the test projects will not be able to resolve the snapshot version of m2e core they are testing against.
Once you are on the correct branch, perform a project import in this order:
You may need to Update Maven (forcing update of snapshot releases) and 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.