Problem using systemtap with context_switch function and $next

Issue

semantic error: failed to retrieve location attribute for local 'next' (dieoffset: 0x30c568): identifier '$next' at ./switch_ctx.stp:6:42

when using following script:

/*#!/usr/bin/env stap
*/

probe kernel.function("context_switch")
{
printf("%s -> %d \n",thread_indent(1),$next->pid)
}