testbed-idp requires to be run from a JDK?

[Tom Zeller]

> This presumably from deep within Jetty when it tries to render the page.
> Switching to using a JDK is no problems and fixes the issue, but it's not
> feasible for customers.

See ${idp.home}/jetty-base/start.d/jsp.ini.

One workaround is to change the JSP impl to Glassfish from Apache in
${idp.home}/jetty-base/start.d/jsp.ini :

jsp-impl=glassfish
-Dorg.apache.jasper.compiler.disablejsr199=true