It seems that you are experiencing some difficulties when trying to use Houdini with the Cycles renderer. Here are a few things you could try to troubleshoot the issue:
Make sure that you have the correct version of Cycles installed. You mentioned that you built Cycles from source, so it’s possible that there could be a version mismatch between the Cycles version you have and the version that Houdini is expecting.
Check the Houdini documentation to see if there are any specific requirements or settings that you need to enable in order to use the Cycles renderer with Houdini.
Check the Hydra logs to see if there are any error messages or warnings that could provide some insight into the issue.
Try using a different renderer, such as Mantra, to see if the issue is specific to the Cycles renderer or if it’s a more general issue with Houdini and external renderers.
If all else fails, you could try reaching out to the Houdini community or the Cycles development team to see if they have any suggestions or solutions.
I hope these suggestions help you to troubleshoot the issue and get Houdini and Cycles working together properly. Good luck!