I’ve been using this process for debugging the installer while launched from a Debian Live desktop. Having a full live environment at your disposal during install is a boon to debugging because you don’t have to work within the constraints normally imposed upon you by the limited debian-installer environment. Caveat: running debian-installer from the debian-installer-launcher still has one or two unresolved issues, so unless you’re specifically working on live integration issues like I am, compare with a conventional d-i image install to gain the added confidence the install is the same in both environments.
There are no longer active maintainers working on debian-installer-launcher and live-installer, and I think it’s really important for wheezy to release with solid support for live installs, so I’ve been using this setup to try to solve #702335. So far, progress is slow because I’m new to this. If anyone is interested in collaborating in this work, give me a shout. I am SynrG @ irc.oftc.net and can be found on #debian-live and #debian-boot if you would like to drop in.
- Use images/lxde-desktop config from live-images.git and build your own image with live-build >=3.0.1-1. Just add “-b hdd” in auto/config before starting your build, as having a read/writable image is handy for this exercise.
- Boot the live medium. You may prefer to do this in a VM for convenience, having prepared a blank virtual disk image as your target in advance.
- Make any small changes you want to the installer before launching it. A quick hack I’ve used is to “sudo vi /usr/sbin/debian-installer-launcher” and near the end on the line after “prepare” right before “run”, open a new line and add “bash” so an interactive shell will be opened after the installer is extracted but before it is launched. For larger changes (e.g. inclusion of updated udebs, etc.) add them to your live image configuration before building as described in live-manual.
- Open two root terminals and do “debian-installer-launcher -t debug” in one and “tail -f /lib/live/installer/var/log/syslog” in the other. If you’ve added the hack from step 3, don’t forget to “exit” the interactive shell after making changes. Now you can watch debug output as you go through the steps of the installer. If you like, you may append additional boot prompt parameters (e.g. preseeds) to the debian-installer-launcher command.
- During the install, you may modify other parts of the unpacked installer under /lib/live/installer (e.g. to add ‘set -x’ to some scripts) prior to executing steps that would call them.