I've come to find that it's because Ubuntu doesn't include the files and
work-around necessary to allow installation to btrfs filesystem. I
recommend including a check/prompt to ensure that 1 MB exists at the
beginning of the drive to allow the use of btrfs as the root file system
as not having
*** This bug is a duplicate of bug 1059827 ***
https://bugs.launchpad.net/bugs/1059827
You mean your first partition starts on sector 63 instead of 2048? The
latter has been the standard now for several years.
** This bug has been marked a duplicate of bug 1059827
Non trival grub2
