Currently on a 64bit OS (Linux/Windows/Solaris?) Hudson will favour the 64bit
JVM if available.

However for projects that need JNI this can lead to test failures if you only
create a 32bit library. The only way to do this is then re-package the JDK and
provide it on a web server for hudson to re-consume (which defeats the purpose
of the ease of deploying new JVMs.)

Conversley you might only want to run on a 64bit JDK if you require a large heap.

Therefore this request is to add a new option to the UI to
1) force a 64bit JDK (this will then prevent a Java tool being available on
32bit platforms)
2) force a 32bit JDK to be installed on 64bit platforms.

e.g.

the user can create a JDK "JDK 1.6.0_14 (32bit)" with "force 32bit JDK on 64bit
hosts=true" and choose that as their java vm for the project and let it run on
any node. knowing that it will only ever run on a 32bit JDK.

They could also do the inverse such as choosing a 64bit JDK and then using a
64bit lable tie the job to a 64bit host.