An exception has occurred in the compiler (1.5.0). Please file a bug at the Java Developer Connection (http://java.sun.com/webapps/bugreport)  after checking the Bug Parade for duplicates. Include your program and the following diagnostic in your report.  Thank you.

java.lang.AssertionError: writePool E

at com.sun.tools.javac.jvm.ClassWriter.writePool(ClassWriter.java:513)
at com.sun.tools.javac.jvm.ClassWriter.writeClassFile(ClassWriter.java:1333)
at com.sun.tools.javac.jvm.ClassWriter.writeClass(ClassWriter.java:1211)
at com.sun.tools.javac.main.JavaCompiler.genCode(JavaCompiler.java:325)
at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:474)
at com.sun.tools.javac.main.Main.compile(Main.java:592)
at com.sun.tools.javac.main.Main.compile(Main.java:544)
at com.sun.tools.javac.Main.compile(Main.java:58)
at com.sun.tools.javac.Main.main(Main.java:48)
make: *** [out/target/common/obj/APPS/VpnServices_intermediates/classes-full-debug.jar] Error 41
make: *** Waiting for unfinished jobs....

After trying the most recent update of Java 1.5 I made a cry for help in the XDA forums. The answer seemed simple enough, try JDK1.6. I installed it and modified /home/ben/mydroid/build/core/main.mk, commenting out the lines that checked for Java 1.5. Then after a "make clean", and another "make -j2" (-j4 made my laptop burn up ...) it was building again, and this time finished!

I make a nandroid backup and wiped to factory settings (using Amon_RA's recovery image) flashed the resulting boot.img and system.img to my phone using fastboot:

fastboot flash boot boot.img
fastboot flash system system.img
fastboot reboot

Rebooted my device, and it worked! A very basic system though, no Market or Google Apps.

Next steps ... getting root, creating an update.zip, making my own kernel with compcache ... the list is actually endless, it's nice just to get this far.

In fact next step could be building from Cyanogen's Eclair sources. Will give it a go and post if it works...

This is not rocket science by the way - this is my experience in following the guides from Google and HTC on Ubuntu 9.10. All of this information is already out there, just not necessarily all in one place in this format or adapted for this environment.

Building on Windows is not supported. I'm using Ubuntu 9.10 (32bit) on my laptop. Java JDK 1.5 is required, using 1.6 is supported but you have to make additional steps changing instances of "1.5" to "1.6" in makefiles. 64bit Ubuntu users may want to follow a different guide, not sure if any differences here could cause a build to fail.

Setting up your environment ready for development, install the following packages (reference):

sudo apt-get install git-core gnupg sun-java5-jdk flex bison gperf libsdl-dev libesd0-dev libwxgtk2.6-dev build-essential zipcurl libncurses5-dev zlib1g-dev valgrind

In Ubuntu 9.10 you can't get Java 1.5 using apt any more. I downloaded it from java.com and installed it in /usr/local/java/jdk1.5.0. Then:

ln -s /usr/local/java/jdk1.5.0/bin/java /usr/local/bin/java

If you try "java -version" it should tell you "Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-b64)". Finally, edit your ~/.bashrc using vim and add the following to the end of the file:

export JAVA_HOME=/usr/local/java/jdk1.5.0/
export ANDROID_JAVA_HOME=$JAVA_HOME
export PATH=$PATH:/home/ben/bin:$JAVA_HOME/bin

Reload your .bashrc file using ". ~./bashrc".

Setting up repo - a Google tool to manage your Android source code repository:

cd ~
mkdir bin
curl http://android.git.kernel.org/repo >~/bin/repo
chmod a+x ~/bin/repo
mkdir mydroid
cd mydroid
repo init -u git://android.git.kernel.org/platform/manifest.git -b eclair

Answer the questions where prompted and then fetch the source code using:

repo sync

This bit takes a while ... when finished:

gpg --import

Paste in the GPG key at the bottom of this page and then press ctrl+D. Now we need the HTC binaries and kernel source to build specifically for the Sapphire.

wget --referer=http://developer.htc.com/google-io-device.html http://member.america.htc.com/download/RomCode/ADP/signed-google_ion-ota-14721.zip?

# line commented -- wget --referer=http://developer.htc.com/ http://member.america.htc.com/download/RomCode/Source_and_Binaries/sapphire.hep-357975db.tar.bz2

Now to do the final bit of setup and start the build (reference here):

cd ~/mydroid/vendor/htc/sapphire-open
./unzip-files.sh
cd ~/mydroid
. build/envsetup.sh
lunch aosp_sapphire_us-eng

Yes that is supposed to say "lunch", not "launch". Now the build can be started! One final thing is required to stop the build from crashing (reference):

cd ~/mydroid/external/webkit
git cherry-pick 18342a41ab72e2c21931afaaab6f1b9bdbedb9fa

Now we can start the build:

cd ~/mydroid
make -j4

Bah, I've got an error: "Your version is: /bin/bash: javac: command not found.". There's a problem with my path (which I have corrected above already).

export PATH=$PATH:$JAVA_HOME/bin

Now it's building. The HTC website advises this is now a good time to make a cup of tea, or take a nap. I'll revisit this tomorrow I think!