SAML development

["Peter W. Morreale" <pmorreale@novell.com>]

I've been tasked with creating a SAML authentication (SSO) module for a
YAWS web server we are creating. 

My question is how does one go about debugging during development?  

Are there any such things as "SAML development" websites that return
error logs for malformed requests?  

Thanks for any and all pointers...

Best
-PWM