Karaf Cellar uses Maven as its build tool.
A normal build
Doing a Quick Build
The following avoids running all the unit test cases, we just skip the test running phase and not the building part
mvn -Dmaven.test.skip=true clean install
mvn -DskipTests clean install
Using an IDE
If you prefer to use an IDE then you can auto-generate the IDE's project files using maven plugins. e.g.
Importing into Eclipse
If you have not already done so, you will need to make Eclipse aware of the Maven repository so that it can build everything. In the preferences, go to Java->Build Path->Classpath and define a new Classpath Variable named M2_REPO that points to your local Maven repository (i.e., ~/.m2/repository on Unix and c:\Documents and Settings\<user>\.m2\repository on Windows).
You can also get Maven to do this for you:
mvn eclipse:add-maven-repo -Declipse.workspace=/path/to/the/workspace/
Building source jars
If you want to build jar files with the source code, that for instance Eclipse can important so you can debug the Karaf code as well. Then you can run this command from the karaf root folder:
mvn clean source:jar install -Dtest=false