These are notes I made while creating a new xvm hypervisor on Precise:

• create schroot with 'sbuild-createchroot /srv/chroot/precise-amd64-sbuild ​http://mirrors.mit.edu/ubuntu'
• defang init inside the schroot:

  dpkg-divert --local /sbin/initctl
  mv /sbin/initctl /sbin/initctl.distrib
  ln -s /bin/true /sbin/initctl
  

• created /usr/sbin/policy-rc.d inside the chroot, containing:

  #!/bin/sh
  
  exit 101
  

• I had to apply the patch from ​http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=471747 to the version of sbuild in Hardy to make the invirtibuilder work for precise

• Right now, to build from a tag instead of a branch name with the invirtibuilder, you need to specify the commit that the tag points to, with the syntax

  (tagname)^{} 
  

  I'll fix this.

• `create-sbuildchroot' didn't install any locales, so I had to:

  apt-get install --no-install-recommends language-pack-en
  

  (--no-install-recommends because otherwise it pulls in bits of Firefox)

• Xen: if you create a hypervisor VM with virt-install or friends, you'll need to go back in afterwards and turn all the virtio devices back to emulated ones. Xen straight up cannot deal with them and will fail in mysterious ways.
• Xen: Just installing the Xen system and rebooting into it will break serial console in several ways. You need:

in /etc/default/grub:

GRUB_CMDLINE_XEN="loglvl=all guest_loglvl=all com1=38400,8n1 console=com1"
GRUB_CMDLINE_LINUX="console=hvc0 earlyprintk=xen"

in /etc/init/ttyS0.conf: change 'ttyS0' to 'hvc0' and restart ttyS0

• Xen: Also, disable the splash screen, quiet-boot, and kernel modesetting, or you'll go mad trying to debug boot problems

• Xen: At some point, the writers of the sample Xen configuration decided to start using '${}' in comments. Unfortunately, this breaks mako. I had to track that down and modify the script that generates the mako template to get rid of it too.