How do I install rEFInd on a MacBook running macOS Sierra? I've disabled SIP and tried to install rEFInd on my MacBook, which is not partitioned in any way by boot camp and is one single drive. The install of rEFInd says it is installing to /Volumes/ESP for the EFI boot and completes successfully. After rebooting, however, rEFInd menu does not come up when holding option key or anything. How do I get that installed so that it is usable?
After reading through the refind-install script (at version 0.10.4), I discovered that all I needed to do was make sure that the EFI partition was mounted.


From the terminal, run diskutil list to find the EFI partition. In my case this was /dev/disk0s1. 
Mount the EFI partition from the location identified in step 1. For me this was mount /dev/disk0s1
Run the rEFInd install script (from the unzipped rEFInd directory): sudo ./refind-install


I got friendly output in my terminal: Installation has completed successfully. After this rEFInd worked on my MacBook Pro.