hmm, well I put this back in, but it seems like the bootloader is broken for wheezy

---
root@dib-xenial:/boot/grub# /usr/sbin/grub-install '--modules=biosdisk part_msdos' --force /dev/loop8
/usr/sbin/grub-probe: error: cannot find a GRUB drive for /dev/mapper/loop8p1.  Check your device.map.
Auto-detection of a filesystem of /dev/mapper/loop8p1 failed.
Try with --recheck.
If the problem persists please report this together with the output of "/usr/sbin/grub-probe --device-map="/boot/grub/device.map" --target=fs -v /boot/grub" to <email address hidden>
root@dib-xenial:/boot/grub# /usr/sbin/grub-probe --device-map="/boot/grub/device.map" --target=fs -v /boot/grub
/usr/sbin/grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd0.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: scanning hd0 for LVM.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: no LVM signature found.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0,msdos1.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0,msdos1.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: scanning hd0 for LVM.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: no LVM signature found.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: scanning hd0,msdos1 for LVM.
/usr/sbin/grub-probe: info: the size of hd0 is 167772160.
/usr/sbin/grub-probe: info: no LVM signature found.
/usr/sbin/grub-probe: info: changing current directory to /dev/mapper.
/usr/sbin/grub-probe: info: changing current directory to /dev/mapper.
/usr/sbin/grub-probe: info: changing current directory to /dev/mapper.
/usr/sbin/grub-probe: info: no mapping exists for `/dev/mapper/loop8p1'.
/usr/sbin/grub-probe: error: cannot find a GRUB drive for /dev/mapper/loop8p1.  Check your device.map.
---

I really don't have the inclination to look into this ... it may have been broken for some time because I don't think we were ever testing "stable" ... only testing (which has become stretch)

There's a few bugs out there on this, but they talk about dm-crypt and lvm and things we're not exactly touching.  

I'm not sure what to do here.  If we don't have a working way to build and image with a bootloader, maybe we should just deprecate it to make it clear...