Comment # 15 on bug 984302 from Stefan Hundhammer

Then there is the bootloader installation:

2016-07-01 10:20:50 <1> linux-terz(2994) [Ruby] bootloader/sysconfig.rb:68
Saving /etc/sysconfig/bootloader for grub2
2016-07-01 10:20:50 <1> linux-terz(2994) [Ruby] modules/Bootloader.rb:406
Calling bootloader executable
2016-07-01 10:20:50 <1> linux-terz(2994) [Ruby] routines/lib_iface.rb:295
Updating bootloader configuration
2016-07-01 10:20:53 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:28
MBRUpdate: activate: true generic: true
2016-07-01 10:20:53 <1> linux-terz(2994) [Ruby] modules/BootStorage.rb:383
Partitions building /dev/sda5: {}
2016-07-01 10:20:53 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:266
Bootloader partition type can be logical
2016-07-01 10:20:53 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:275
Partition for activating: {"num"=>5, "mbr"=>"/dev/sda"}
2016-07-01 10:20:53 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:60
Creating backup of boot sectors of ["/dev/sda", "/dev/sda5"]
2016-07-01 10:20:54 <3> linux-terz(2994) [bash]
ShellCommand.cc(shellcommand):78 1+0 records in
2016-07-01 10:20:54 <3> linux-terz(2994) [bash]
ShellCommand.cc(shellcommand):78 1+0 records out
2016-07-01 10:20:54 <3> linux-terz(2994) [bash]
ShellCommand.cc(shellcommand):78 512 bytes (512 B) copied, 7.228e-05 s, 7.1
MB/s
2016-07-01 10:20:54 <1> linux-terz(2994) [Ruby] routines/i386.rb:100 MBR of
/dev/sda contains ThinkPad sequence: false
2016-07-01 10:20:54 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:266
Bootloader partition type can be logical
2016-07-01 10:20:54 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:275
Partition for activating: {"num"=>5, "mbr"=>"/dev/sda"}
2016-07-01 10:20:54 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:85
Copying generic MBR code to /dev/sda
2016-07-01 10:20:54 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:71 mbr
type = gpt
2016-07-01 10:20:54 <3> linux-terz(2994) [bash]
ShellCommand.cc(shellcommand):78 1+0 records in
2016-07-01 10:20:54 <3> linux-terz(2994) [bash]
ShellCommand.cc(shellcommand):78 1+0 records out
2016-07-01 10:20:54 <3> linux-terz(2994) [bash]
ShellCommand.cc(shellcommand):78 440 bytes (440 B) copied, 0.0181934 s, 24.2
kB/s
2016-07-01 10:20:54 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:89
Command `/bin/dd bs=440 count=1 if=/usr/share/syslinux/gptmbr.bin of=/dev/sda`
output: {"exit"=>0, "stderr"=>"1+0 records in\n1+0 records out\n440 bytes (440
B) copied, 0.0181934 s, 24.2 kB/s\n", "stdout"=>""}
2016-07-01 10:20:54 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:266
Bootloader partition type can be logical
2016-07-01 10:20:54 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:275
Partition for activating: {"num"=>5, "mbr"=>"/dev/sda"}
2016-07-01 10:20:54 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:71 mbr
type = gpt
2016-07-01 10:20:54 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:141
Activating partition 5 on /dev/sda
2016-07-01 10:20:54 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:71 mbr
type = gpt
2016-07-01 10:20:54 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:109
Command `/usr/sbin/parted -sm /dev/sda print` output: {"exit"=>0, "stderr"=>"",
"stdout"=>"BYT;\n/dev/sda:500GB:scsi:512:512:gpt:ATA SAMSUNG
HM500JI:;\n1:20.5kB:210MB:210MB:fat32:EFI System
Partition:boot;\n2:210MB:131GB:131GB:hfs+:mac:;\n3:131GB:352GB:221GB::WIN:;\n4:352GB:352GB:156MB::primary:bios_grub;\n5:352GB:500GB:148GB:ext4:primary:;\n"}
2016-07-01 10:20:54 <1> linux-terz(2994) [Ruby] bootloader/mbr_update.rb:102
Command `/usr/sbin/parted -s /dev/sda set 5 legacy_boot on` output: {"exit"=>0,
"stderr"=>"", "stdout"=>""}
2016-07-01 10:21:13 <1> linux-terz(2994) [Ruby] routines/lib_iface.rb:337
Initializing bootloader ret: 1
2016-07-01 10:21:13 <1> linux-terz(2994) [Ruby] modules/BootGRUB2.rb:119 GRUB
return value: true
2016-07-01 10:21:13 <1> linux-terz(2994) [Ruby] routines/i386.rb:100 MBR of
/dev/sda contains ThinkPad sequence: false
2016-07-01 10:21:15 <1> linux-terz(2994) [Ruby] bootloader/grub2base.rb:52
parted disk_set pmbr: {"exit"=>0, "stderr"=>"", "stdout"=>""}

Josef, AFAICS it overwrites the MBR and activates partitions. Is that the right
thing to to on a MacBook with EFI and GPT?