Argument declarations for probe definitions cannot be declared with derived types such as enum, struct, or union.

The following compiler warning can be ignored for probe definition arguments of type string (which is a D type but not a C type):

provider_def.h:line#: warning: parameter names (without types) in function declaration

Multi-threaded processes under ustack(), usym(), uaddr() and umod() which perform dlopen() in threads other than the first thread may not have accurate symbol resolution for symbols introduced by the dlopen(). (Bug ID 20045149)