90apt-sources breaks sources.list in focal builds

[Scott Moser]

the file '/etc/schroot/setup.d/90apt-sources' attempts to enable 'APT_POCKETS' (release, security, updates, proposed). It attempts to change the existing /etc/apt/sources.list.

sources.list in 'livecd.ubuntu-base.rootfs.tar.gz'
releases before have focal an /etc/apt/sources.list with just one line like:

$ tar xvzf bionic-livecd.ubuntu-base.rootfs.tar.gz --to-stdout chroot-autobuild/etc/apt/sources.list
chroot-autobuild/etc/apt/sources.list
deb http://archive.ubuntu.com/ubuntu/ bionic main restricted universe multiverse

But focal's has a "full" /etc/apt/sources.list:
$ tar xvzf focal-livecd.ubuntu-base.rootfs.tar.gz --to-stdout chroot-autobuild/etc/apt/sources.list | pastebinit
chroot-autobuild/etc/apt/sources.list
https://paste.ubuntu.com/p/WKJmnBmhC5/

The parsing/updating of APT_POCKETS breaks with the more complicated sources.list

Here is the failure recreate:

$ sbuild --dist=focal --arch=amd64 --arch-all ../out/cloud-init_20.1-10-g71af48df-0ubuntu4.dsc
sbuild (Debian sbuild) 0.79.0 (05 February 2020) on crabapple

+===============================================================================+
| cloud-init 20.1-10-g71af48df-0ubuntu4 (amd64) Fri, 17 Apr 2020 17:22:32 +0000 |
+===============================================================================+

Package: cloud-init
Version: 20.1-10-g71af48df-0ubuntu4
Source Version: 20.1-10-g71af48df-0ubuntu4
Distribution: focal
Machine Architecture: amd64
Host Architecture: amd64
Build Architecture: amd64
Build Type: binary

I: 01launchpad-chroot: [focal-amd64] Processing config
I: 01launchpad-chroot: [focal-amd64] Already up to date.
I: 90apt-sources: setting apt pockets to 'release security updates proposed' in sources.list
I: 90apt-sources: setting apt components to 'main universe' in sources.list
I: NOTICE: Log filtering will replace 'var/run/schroot/mount/focal-amd64-21104d17-1db3-4a70-bcbd-3479c4d29227' with '<<CHROOT>>'
I: NOTICE: Log filtering will replace 'build/cloud-init-j9cjIs/resolver-pDIVK5' with '<<RESOLVERDIR>>'

+------------------------------------------------------------------------------+
| Update chroot |
+------------------------------------------------------------------------------+

E: Type 'main' is not known on line 5 in source list /etc/apt/sources.list
E: The list of sources could not be read.
E: apt-get update failed

+------------------------------------------------------------------------------+
| Summary |
+------------------------------------------------------------------------------+

Build Architecture: amd64
Build Type: binary
Build-Space: 0
Build-Time: 0
Distribution: focal
Fail-Stage: apt-get-update
Host Architecture: amd64
Install-Time: 0
Job: ../out/cloud-init_20.1-10-g71af48df-0ubuntu4.dsc
Machine Architecture: amd64
Package: cloud-init
Package-Time: 0
Source-Version: 20.1-10-g71af48df-0ubuntu4
Space: 0
Status: failed
Version: 20.1-10-g71af48df-0ubuntu4
--------------------------------------------------------------------------------
Finished at 2020-04-17T17:22:32Z
Build needed 00:00:00, 0k disk space
E: apt-get update failed

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: sbuild-launchpad-chroot 0.16
ProcVersionSignature: Ubuntu 5.3.0-46.38~18.04.1-generic 5.3.18
Uname: Linux 5.3.0-46-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Fri Apr 17 13:17:49 2020
InstallationDate: Installed on 2020-01-15 (92 days ago)
InstallationMedia: Ubuntu 18.04.3 LTS "Bionic Beaver" - Release amd64 (20190805)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: sbuild-launchpad-chroot
UpgradeStatus: Upgraded to focal on 2020-04-17 (0 days ago)

[Launchpad Janitor (janitor)]

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