== Warning ==
 Do not build as root,always build as user.
== Setup ==
Get and install the repo tool
{{{
 mkdir bin
 cd bin
 wget http://android.git.kernel.org/repo
 chmod a+x repo
 cd ..
}}}
Get replicant 2.2
{{{
 mkdir replicant-2.2
 cd replicant-2.2
 ../bin/repo init -u git://gitorious.org/replicant/manifest.git -b replicant-2.2
 ../bin/repo sync
}}}

== Each time you want to build replicant 2.2 ==
{{{
cd ~/replicant-2.2
 ../bin/repo sync
source build/envsetup.sh
export ANDROID_JAVA_HOME=$JAVA_HOME
lunch cyanogen_dream_sapphire-eng 
make -j$(echo "$(grep 'processor' /proc/cpuinfo | wc -l ) + 1" | bc) bacon  #uses arguments like -j9 to speed up build in case of multi-core cpu
}}}
Don't forget the bacon at the end, without that you will have some builds errors.
Note that the bacon also produces standard images like system.img, just ship the system.img like images