Building Maven yourself is for one of two reasons:
Note, that you don't need to bootstrap Maven for day to day use, or to develop plugins. While we encourage getting involved and fixing bugs that you find, for day to day use we recommend using the latest release.
All of the source code for Maven and its related libraries is in Subversion. You can browse the repository, or checkout specific modules directly.
To build Maven 3 (the current stable branch), you need the trunk of the maven-3 module. To check that out, run the command:
svn co https://svn.apache.org/repos/asf/maven/maven-3/trunk/ maven-3
To build Maven 2, you need the maven-2.2.x branch of the maven-2 module. To check that out, run the command:
svn co https://svn.apache.org/repos/asf/maven/maven-2/branches/maven-2.2.x maven-2.2.x
Alternatively, you can check out all Maven projects in one directory using:
svn co https://svn.apache.org/repos/asf/maven/trunks maven
If you have checked out trunks, the maven-2.2.x directory will contain the Maven 2.2 source code, and the maven-3 directory will contain the 3.0 source code. Note that neither directory contains any of the plugins.
Note: For Windows users, the checkout could be not complete with the following message:
svn: Can't open file 'XXX': The system cannot find the path specified.
The problem is that while Windows allows filenames up to 256 characters the maximum path length it allows is 260 characters. You will be able to check it out to the root directory without problem.
Other modules you might be interested in related to Maven development are:
If you're looking at the trunks directory with ViewVC, there is seemingly nothing there. We use externals definitions to link together all the trunks into one logical location for convenience. If you want to see what is being linked into one logical location you can use the following command:
svn propget svn:externals
If you already have Maven installed, it can be faster to build a new version with Maven, rather than a clean bootstrap.
To do this, run from the maven-3 or maven-2.2.x directory:
mvn install
Optionally, you can use the following to run the full (long) suite of integration tests:
mvn install -Prun-its
The assemblies will be created in apache-maven/target for Maven 2.0.x or maven-distribution for Maven 2.1, and can be unzipped to the location where you'd like Maven installed.
If you do not have Maven installed, you can use Apache Ant to build Maven.
Once you have checked out the code, change into the maven-3 or maven-2.2.x directory that was created.
Set the M2_HOME environment variable to the location that should contain Maven. This directory must be named after the Maven version you want to build and install, for example /usr/local/maven-2.2-SNAPSHOT.
export M2_HOME=/usr/local/maven-2.2-SNAPSHOT PATH=$M2_HOME/bin:$PATH
or
set M2_HOME=c:\maven-2.2-SNAPSHOT set PATH=%M2_HOME%\bin;%PATH%
From this, run the ant command:
ant
This will download dependencies, build Maven, and install it into the directory you specified as M2_HOME above.
If you have any problems or get any failures during the run, please report them to the Maven Developers List.
For more information, consult the project help in the Ant build file.
ant -projecthelp
The result is included here for convenience:
Buildfile: build.xml
The first time you build Maven from source, you have to build Maven without
Maven. This Ant script builds a minimal Maven, just enough to re-launch
Maven again in this directory and generate an installation assembly. Then we
extract the assembly and re-run the Maven build one more time, this time
with the full generated Maven.
To run this script, you must set the M2_HOME environment variable or the
maven.home property to the location that should contain Maven. This
directory *must* be named after the maven version you want to install, e.g.
/usr/local/maven-2.1-SNAPSHOT.
You can set the maven.repo.local property to specify a custom location for
your local repository for the bootstrap process.
Main targets:
classpath-pre constructs a classpath reference containing our dependencies,
and verifies that all files are present
clean-bootstrap cleans up generated bootstrap classes
compile-boot compiles the bootstrap sources
extract-assembly extracts the maven assembly into maven.home
generate-sources generates Java sources from Modello mdo model files
maven-assembly generates the Maven installation assembly using the bootstrap
Maven
maven-compile compiles Maven using the bootstrap Maven, skipping automated
tests
pull copies all required dependencies from the Maven remote
repository into your local repository. Set the 'skip.pull'
property to skip this step, but only if you're sure you
already have all of the dependencies downloaded to
your local repository
run-full-maven runs the full extracted Maven, now with tests
Default target: all