Even though TYPO3 Flow, TYPO3 Neos and Fluid are pretty well documented you can get sometimes a little bit lost when looking for specific information. Especially the usability of the official TYPO3 websites is not really great, as the page structure is IMO not well thought-out. And not to tell about the search functionality, which is currently pretty useless in most cases (e.g. have you ever tried to search for a Fluid ViewHelper on docs.typo3.org? Not quite the definition of meaningful search results…).
In case you wanted to try out the new Content Management System TYPO3 Neos, either in a Beta version or in version 1.0, you may have come across a weird problem when installing it on your local development environment on your Mac.