Hi there,
As the documentation notes, if you intend to install the application on a Mac-based server, we strongly recommend virtualization (i.e. using something like VMWare), and then following the recommended Ubuntu installation instructions inside your virtual environment. Many of the libraries and packages used in AtoM may not be available on Mac, or if they are, may have different defaults, versions, and configuration options. At Artefactual, we only test and develop AtoM on Linux Ubuntu, so we are unable to offer guidance on how you would alter the recommended installation instructions to work natively on MacOS. I'm hoping that perhaps someone in our community might have further guidance to offer.
Keep in mind as well that AtoM is intended for use in production when installed on a server - not on a desktop computer! If by OSX you mean you are trying to install AtoM on a personal computer, please note that we strongly recommend against this for a production installation. If you are just looking for a testing and development environment, you might want to check out the AtoM Vagrant box - it can easily be installed using Virtualbox on a personal computer running any operating system. See:
Regards,