how do i edit the boot process to avoid this message during linux install? “Executing 'grub-install/dev/sda' failed. This is в фатальную ошибку.”

during install of linux on в macbook pro 6,2 (2010) схвати в single boot system, i am getting the following ошибка with the linux installer on the live usb: "Executing 'grub-install/dev/sda' failed. This is в фатальную ошибку." I had в previously 'successful' install of mint but it crashed presumably due to в видео issue. i am not interested in having the mac вы on the machine at all. it appears there is an EFI partition on sda for the grub install (i am assuming this is where grub gets installed?). i ran the 'bootinfoscript' and the results follow below. any thoughts пашите appreciated. thank you:

============================= Boot Info Summary: ===============================
 => No boot loader is installed in the MBR of /dev/sda.
 => No known boot loader is installed in the MBR of /dev/sdc.
sda1: __________________________________________________________________________
    File system:       vfat
    Boot sector type:  FAT32
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        
sda2: __________________________________________________________________________
    File system:       swap
    Boot sector type:  -
    Boot sector info: 
sda3: __________________________________________________________________________
    File system:       ext4
    Boot sector type:  -
    Boot sector info: 
    Operating System:  Linux Mint 17.2 Rafaela
    Boot files:        /etc/fstab
sdc1: __________________________________________________________________________
    File system:       iso9660
    Boot sector type:  Unknown
    Boot sector info: 
    Mounting failed:   mount: /dev/sdc1 already mounted or sdc1 busy
sdc2: __________________________________________________________________________
    File system:       vfat
    Boot sector type:  FAT16
    Boot sector info:  According to the info in the boot sector, sdc2 starts 
                       at sector 0. But according to the info from fdisk, 
                       sdc2 starts at sector 3173944. According to the info 
                       in the boot sector, sdc2 has 0 sectors.
    Mounting failed:   mount: /dev/sdc1 already mounted or sdc1 busy
mount: /dev/sdc2 already mounted or sdc2 busy
============================ Drive/Partition Info: =============================
Drive: sda _____________________________________________________________________
Disk /dev/sda: 320.1 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
Partition  Boot  Start Sector    End Sector  # of Sectors  Id System
/dev/sda1                   1       976,895       976,895  ee GPT
/dev/sda2    *    609,517,568   625,141,759    15,624,192  82 Linux swap / Solaris
/dev/sda3             976,896   609,517,567   608,540,672  83 Linux
GUID Partition Table detected.
Partition    Start Sector    End Sector  # of Sectors System
/dev/sda1           2,048       976,895       974,848 EFI System partition
/dev/sda2     609,517,568   625,141,759    15,624,192 Swap partition (Linux)
/dev/sda3         976,896   609,517,567   608,540,672 Data partition (Linux)
Drive: sdc _____________________________________________________________________
Disk /dev/sdc: 8154 MB, 8154250752 bytes
255 heads, 63 sectors/track, 991 cylinders, total 15926271 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
Partition  Boot  Start Sector    End Sector  # of Sectors  Id System
/dev/sdc1    *              0     3,186,175     3,186,176   0 Empty
/dev/sdc2           3,173,944     3,178,615         4,672  ef EFI (FAT-12/16/32)
/dev/sdc1 overlaps with /dev/sdc2
GUID Partition Table detected, but does not seem to be used.
Partition    Start Sector    End Sector  # of Sectors System
/dev/sdc1               0     3,186,119     3,186,120 Data partition (Windows/Linux)
/dev/sdc2       3,173,944     3,178,615         4,672 Data partition (Windows/Linux)
"blkid" output: ________________________________________________________________
Device           UUID                                   TYPE       LABEL
/dev/loop0                                              squashfs   
/dev/sda1        C427-EC39                              vfat       
/dev/sda2        7711ab90-830e-4a97-85ce-870caab06621   swap       
/dev/sda3        cc7fd146-7e0e-46dd-b029-3a3adb7daf6c   ext4       
/dev/sdc1                                               iso9660    Linux Mint 17.2 Cinnamon 64-bit
/dev/sdc2        3006-9304                              vfat       
================================ Mount points: =================================
Device           Mount_Point              Type       Options
/dev/loop0       /rofs                    squashfs   (ro,noatime)
/dev/sdc         /cdrom                   iso9660    (ro,noatime)
=============================== sda3/etc/fstab: ================================
--------------------------------------------------------------------------------
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda3 during installation
UUID=cc7fd146-7e0e-46dd-b029-3a3adb7daf6c /               ext4    errors=remount-ro 0       1
# /boot/efi was on /dev/sda1 during installation
UUID=C427-EC39  /boot/efi       vfat    defaults        0       1
# swap was on /dev/sda2 during installation
UUID=7711ab90-830e-4a97-85ce-870caab06621 none            swap    sw              0       0
--------------------------------------------------------------------------------
=================== sda3: Location of files loaded by Grub: ====================
           GiB - GB             File                                 Fragment(s)