In the Mac OS X El Capitan release, Apple has added a new layer named System Integrity Protection (SIP) to its security model. SIP's protections are not limited to protecting the system from file system changes. There are also system calls that are now restricted in their functionality, which can affect developing and debugging on Mac OS X. For runtime protection the following restrictions exist:

However, SIP does not block inspection by the developer of their own applications while they are being developed. TotalView tools will continue to allow applications to be inspected and debugged during the development process.

For more information about SIP, please see Apple's developer documentation.