I have posted on github and other steemit posts on the .dmg and it does not work on my machine running 10.10 so there are limitations such as jiro compiled it with qt5 and its not backwards comparable and requires qt5 and well since that requires 10.11 and it needs to be fixed/worked on for older systems... Similar to why a year ago I worked on the porting on the gridcoinresearchd client to ppc64 and was going to work on Dec Alpha , Mips covering the r4000 to r15k and SGI machines or clones along with sun5c and older as there are so many surplus systems out there that would make great linux/bsd/unix gridcoin nodes although currently only Windows has the neural network so really until then those systems will not help so its /dev/null and mute similar to the client/daemon needs to dump its 1 network port limitation adapted from using the Bitcoin Core code to build the networking layers of this coin with peer/black and what ever other coins Rob google'd and snagged code snippets from. So lets not run all this song and dance , so Gridcoin runs on only the latest and greatest mac hardware and you cannot brew it on older systems.... Sorry but with a model for a Coin that uses the spare un-used idle resources this seems like a model development should not take... Or maybe this was just his first packaging of a .dmg? You can just go cli and compile from source , still does not work since it wants to build the GUI and you have to tell it no.