After CR 7130404 'os.arch' value for JDK 7u5 b02 on macosx became x86_64, but BSD provider rejects any attempts to setup debugger if cpu is not 'x86' or 'amd64':
/export/jdk/jdk1.7.0_05b02/bin/jstack -m $PID
Attaching to process ID 63355, please wait...
Error attaching to process: Bsd only supported on x86/amd64
but with JDK 7u5 b01:
/export/jdk/jdk1.7.0_05b02/bin/jstack -m $PID
Attaching to process ID 63355, please wait...
attach: task_for_pid(63355) failed (5)
Error attaching to process: sun.jvm.hotspot.debugger.DebuggerException: Can't attach to the process
Issue was first introduced in JDK 7u4-b20.
In case if BSD SA provider will be used with macosx it should recognize x86_64 cpu arch name.