Instructions on how to run a secondary mDNSResponder in the Xcode debugger.  (Two known issues, the secondary mDNSResponder will not receive unicast mDNS packets and it does not support BTMM.)

1.) From Terminal shell, open mDNSResponder Xcode project.  

	$ open mDNSMacOSX/mDNSResponder.xcodeproj/

You can also just double click on the project from Finder.

2.) Configure Xcode Project Scheme by adding the following three arguments, -d -NoSandbox -UseDebugSocket.

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3.) Build and run mDNSResponder by setting the target to mDNSResponder.

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	Then execute Command-R to build and run your code with the active scheme.

4.) Before using dns-sd with Xcode-version of mDNSResponder, make sure to export the socket UDS path by executing one of the following commands:

	From a Borne, bash or zsh, execute this command:

		export DNSSD_UDS_PATH=/var/tmp/mDNSResponder

	From csh or tcsh, execute this command:

		setenv DNSSD_UDS_PATH /var/tmp/mDNSResponder

	There may be other variants to setting the environment variable as well for other shells.

	Now running dns-sd  will interoperate with the secondary Xcode-version of mDNSResponder as long as you run dns-sd from this terminal shell.

5.) Now set a breakpoint in Xcode and try to trigger it using dns-sd.