Cannot boot into rEFIt (to choose Ubuntu) on Mac after Yosemite upgrade

Did you reinstall rEFIt manually?

If you didn't, try running this on the OSX Terminal

cd /efi/refit   
./enable.sh

When prompted for your password, use the one Yosemite asks you for while trying to install new software.

After that, you should see the boot menu after you restart. When you choose to load Ubuntu from the boot menu, you may be greeted by the grub rescue> terminal" instead of a normal boot, let me know.

By the way, you can also press the option key (alt) just after you hit the power button, and there you'll see some options, including rEFIt. This has the drawback that it must be done on every boot, hence the preference for the terminal solution.

I had the same problem with a Late 2013 Macbook pro. rEFInd worked for me with the command ./install.sh --esp --alldrivers, although my first impression was that I had failed. I just had to wait ~1 minute for the rEFInd menu to pop up during the boot.

To avoid this long wait at boot, you can make the following adjustments to your rEFInd install.

From OS X:

1. Mount your esp partition.

   mkdir /Volumes/EFI && sudo mount -t msdos /dev/disk0s1 /Volume/EFI
   

2. Rename the rEFInd folder BOOT. eg. /Volumes/EFI/EFI/refind becomes /Volumes/EFI/EFI/BOOT
3. Rename the refind_x64.efi file to bootx64.efi. eg. /Volumes/EFI/EFI/refind/refind_x64.efi becomes /Volumes/EFI/EFI/BOOT/bootx64.efi

Umount and reboot. Enjoy! :)

Booting your Mac via rEFIt please open a terminal and try running this command after installation of rEFit:

cd /efi/refit
./enable.sh

and reboot!