OpenSimulator sources recently added the LSL script function 'osCheckODE()'. This function returns 'true' if the region the script is running on is using the OpenDynamicsEngine physics engine.
The rational behind this addition is that all physics engines should strive to be interchangeable and operate with perfect adherence to the ideal (i.e., SL compatibility). That is, ideally, any script should not care which physics engine is being used.
There are many regions, though, that run the OpenDynamicsEngine ("ODE") physics engine which suffers from operational differences from the ideal and also has a lack of ongoing development. Vehicle scripts that wish to work everywhere must adapt to these differences.
The 'osCheckODE()' function enables scripts to run in two modes: SL compatible mode and ODE compatible mode. This doesn't make testing any easier but this hopefully helps vehicle development tend toward cross grid operation. This function always works even if ossl functions are not enabled.
Script safely and Mantis any bugs.
 I'm carefully not saying "BulletSim mode". The design is that all physics engines should operate the same. The problem here is not BulletSim vs ODE. The problem is that ODE is not being actively developed and it is what it is and it will be just what it is for the foreseeable future.