Injecting the following check-passing rule:

RULE g
CLASS ^java.lang.ThreadLocal
METHOD get
AT ENTRY
IF true
DO traceStack()
ENDRULE

Works only in subclasses of ThreadLocal but not in "java.lang.ThreadLocal" itself. Tried even adding byteman to the boot class path with no success, verbose logging prints steps for ThreadLocal subclasses but not for the base class.