Gaby,
I've checked your mtasc.yaml and have found the following issues with it:
- you need to change the line that reads "trace: console" to "trace: xtrace" - you don't need to add the path to the MTASC binary unless you are using a custom binary. - depending on how you get your application started, you may be missing a "-main" parameter on your parameters line. So, it should be "params: -mx -keep -main". This is assuming you're using the MTASC default behavior of having the main() method start your app.
Your custom build_with_mtasc.rb looks good to me. I'll test your modifications and see if I can include them on the bundle. Thank you very much : )
Please, let me know if this fixes your problem... I understand the documentation is quite sparse about this issue, and would like to hear your comments ; )