Trying to build Debian unstable and testing schroots with mk-sbuild --debootstrap fails

[Ceridwen]

I tried to set up schroots for Debian unstable and testing with the following command:

mk-sbuild --debootstrap-include=devscripts unstable

Each time, the creation eventually failed with the following warning printed five times:

W: Failure while configuring base packages. This will be re-attempted up to five times.
W: See /var/lib/schroot/chroots/sid-amd64/debootstrap/debootstrap.log for details (possibly the package devscripts is at fault)

I've attached the debootstrap.log file. When I created an schroot for stable, that finished. It's possible this is an upstream bug in Debian's version of devscripts, but I figured I would start here since I'm trying to create these schroots on an Ubuntu system. Tell me if I should file this instead against Debian's debootstrap or devscripts.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: debootstrap 1.0.78+nmu1ubuntu1.1
ProcVersionSignature: Ubuntu 4.4.0-24.43-generic 4.4.10
Uname: Linux 4.4.0-24-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_modeset nvidia
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CurrentDesktop: GNOME-Classic:GNOME
Date: Mon Jun 27 23:05:53 2016
InstallationDate: Installed on 2015-06-19 (374 days ago)
InstallationMedia: Ubuntu-GNOME 15.04 "Vivid Vervet" - Release amd64 (20150422)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: debootstrap
UpgradeStatus: Upgraded to xenial on 2016-06-26 (1 days ago)

[Ken Sharp (kennybobs)]

I suspected that this may still occur, but it looks like it fails even earlier now.

Setting up usrmerge (39) ...

FATAL ERROR:
Both /sbin/start-stop-daemon and /usr/sbin/start-stop-daemon exist.

You can try correcting the errors reported and running again
/usr/lib/usrmerge/convert-usrmerge until it will complete without errors.
Do not install or update other Debian packages until the program
has been run successfully.

E: usrmerge failed.
dpkg: error processing package usrmerge (--configure):
 installed usrmerge package post-installation script subprocess returned error exit status 1
dpkg: init-system-helpers: dependency problems, but configuring anyway as you requested:
 init-system-helpers depends on usrmerge | usr-is-merged; however:
  Package usrmerge is not configured yet.
  Package usr-is-merged is not installed.
  Package usrmerge which provides usr-is-merged is not configured yet.

Setting up init-system-helpers (1.66) ...
Processing triggers for libc-bin (2.37-15) ...
Errors were encountered while processing:
 usrmerge

This looks like a Debian bug. I'll come back to this.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.