From 876c5bdf3e718970fb454483901ca94fc4de1721 Mon Sep 17 00:00:00 2001
From: Lyndon Brown <jnqnfe@gmail.com>
Date: Wed, 25 Aug 2021 03:48:53 +0100
Subject: [PATCH] debootstrap: fix use of sysvinit

if the user wants sysvinit rather than systemd, we must instruct
debootstrap to include `sysvinit-core` and exclude `systemd`,
`systemd-sysv` and possibly also `systemd-timesyncd` via the `--include`
and `--exclude` options respectively.

the existing addition of `sysvinit-core` via a chroot package-list was
inadequate to make things work and is redundant now, so it has been removed
from the config script.

unfortunately due to #776917, as explained at [1], debootstrap does not
actually work properly when you try to switch the init system just using
`--include` and `--exclude` as above. i tested this on sid and confirmed
that this is still the case, both the sysvinit packages and the systemd
packages ended up installed together.

thus i have had to implement the workaround from [1] which involves using
debootstrap's alternative two-step mode, and removing systemd from a
package installation list in between.

i found that the details at [1] were a bit outdated so i had to adjust the
solution slightly:
 - the `systemd` and `systemd-sysv` packages are now listed in the `base`
   file rather than `required`. there is also `systemd-timesyncd` there
   which should no doubt also be removed also.
 - the contents of the `required` file is no longer a space separated list,
   though we don't need to modify it anymore. `base` is currently a space
   separated list.

i additionally noted that the `required` file contains `libsystemd0` and i
thus tried removing that, however it turns out that `apt` depends upon it
and removing it consequently causes debootstrap to fail.

the use of the "proper" `--include`/`--exclude` solution remains in this
commit despite not working on its own because it neatly lets the package
cache code include the sysvinit packages in its caching operations.

if/when debootstrap fixes the problem, we can remove everything added here
with the exception of the initial few `--include`/`--exclude` lines.

[1]: https://www.notinventedhere.org/articles/linux/debootstrapping-debian-jessie-without-systemd.html

Gbp-Dch: Short
Closes: #992916
---
 scripts/build/bootstrap_debootstrap | 31 +++++++++++++++++++++++++++++
 scripts/build/config                |  2 +-
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/scripts/build/bootstrap_debootstrap b/scripts/build/bootstrap_debootstrap
index e0278844c..fe8d28f8c 100755
--- a/scripts/build/bootstrap_debootstrap
+++ b/scripts/build/bootstrap_debootstrap
@@ -76,6 +76,11 @@ else
 	DEBOOTSTRAP_OPTIONS="${DEBOOTSTRAP_OPTIONS} --force-check-gpg"
 fi
 
+if [ "${LB_INITSYSTEM}" = "sysvinit" ]
+then
+	DEBOOTSTRAP_OPTIONS="${DEBOOTSTRAP_OPTIONS} --include=sysvinit-core --exclude=systemd,systemd-sysv,systemd-timesyncd"
+fi
+
 if [ "${LB_CACHE_PACKAGES}" = "true" ]
 then
 	if ls cache/packages.bootstrap/*.deb > /dev/null 2>&1
@@ -99,6 +104,17 @@ fi
 Print_breakage
 Echo_message "Running debootstrap..."
 
+Disable_systemd_hack ()
+{
+	# note, these cope with both a space separated list form and one package per line form to
+	# account for potential differences between debootstrap versions.
+	# note, do **not** try to remove `libsystemd0` from `chroot/debootstrap/required`, this is
+	# required by `apt` and will break the setup.
+	sed -i -e 's/ systemd / /g' -e '/systemd/d' chroot/debootstrap/base
+	sed -i -e 's/ systemd-sysv / /g' -e '/systemd-sysv/d' chroot/debootstrap/base
+	sed -i -e 's/ systemd-timesyncd / /g' -e '/systemd-timesyncd/d' chroot/debootstrap/base
+}
+
 # Run appropriate bootstrap, i.e. foreign or regular bootstrap
 if [ "${LB_BOOTSTRAP_QEMU_ARCHITECTURE}" = "${LB_ARCHITECTURE}" ]; then
 
@@ -110,9 +126,24 @@ if [ "${LB_BOOTSTRAP_QEMU_ARCHITECTURE}" = "${LB_ARCHITECTURE}" ]; then
 	Echo_message "Bootstrap will be foreign"
 	debootstrap ${DEBOOTSTRAP_OPTIONS} --foreign "${LB_PARENT_DISTRIBUTION_CHROOT}" chroot "${LB_PARENT_MIRROR_BOOTSTRAP}" ${DEBOOTSTRAP_SCRIPT}
 
+	if [ "${LB_INITSYSTEM}" = "sysvinit" ]; then
+		Disable_systemd_hack
+	fi
+
 	Echo_message "Running debootstrap second stage under QEMU"
 	cp ${LB_BOOTSTRAP_QEMU_STATIC} chroot/usr/bin
 	Chroot chroot /bin/sh /debootstrap/debootstrap --second-stage ${FOREIGN_DEBOOTSTRAP_OPTIONS}
+
+elif [ "${LB_INITSYSTEM}" = "sysvinit" ]; then
+
+	Echo_message "Performing first stage of two-stage setup for sysvinit issue workaround"
+	debootstrap ${DEBOOTSTRAP_OPTIONS} --foreign "${LB_PARENT_DISTRIBUTION_CHROOT}" chroot "${LB_PARENT_MIRROR_BOOTSTRAP}" ${DEBOOTSTRAP_SCRIPT}
+
+	Disable_systemd_hack
+
+	Echo_message "Running debootstrap second stage"
+	Chroot chroot /bin/sh /debootstrap/debootstrap --second-stage ${FOREIGN_DEBOOTSTRAP_OPTIONS}
+
 else
 	debootstrap ${DEBOOTSTRAP_OPTIONS} "${LB_PARENT_DISTRIBUTION_CHROOT}" chroot "${LB_PARENT_MIRROR_BOOTSTRAP}" ${DEBOOTSTRAP_SCRIPT}
 fi
diff --git a/scripts/build/config b/scripts/build/config
index 804401740..3a068536f 100755
--- a/scripts/build/config
+++ b/scripts/build/config
@@ -1372,7 +1372,7 @@ if [ ! -e "${LIVE_PKG_LIST}" ]; then
 				;;
 
 			sysvinit)
-				NEEDED_PACKAGES="${NEEDED_PACKAGES} live-config-sysvinit sysvinit-core"
+				NEEDED_PACKAGES="${NEEDED_PACKAGES} live-config-sysvinit"
 				;;
 		esac
 	fi