Update debhelper (#13594)

* Update debian packaging to debhelper version 12

Don't call dh_installinit anymore, because it has been deprecated, and use
dh_installsystemd instead of dh_systemd_enable for the same reason.

Signed-off-by: Jörg Behrmann <behrmann@physik.fu-berlin.de>

* Drop preinst script

It was used for reasons of interactions of dh_systemd_start and dh_installinit,
which have both be deprecated

Signed-off-by: Jörg Behrmann <behrmann@physik.fu-berlin.de>

* Drop /etc/default file

It was no longer being installed.

* Remove debian/compat file

This is managed by the control file nowadays

debian/changelog

@@ -1,5 +1,7 @@
 matrix-synapse-py3 (1.66.0~rc1+nmu1) UNRELEASED; urgency=medium
 
+  * Update debhelper to compatibility level 12.
+  * Drop the preinst script stopping synapse.
   * Allocate a group for the system user.
 
  -- Jörg Behrmann <behrmann@physik.fu-berlin.de>  Tue, 23 Aug 2022 17:17:00 +0100

debian/control

@@ -4,7 +4,7 @@ Priority: extra
 Maintainer: Synapse Packaging team <packages@matrix.org>
 # keep this list in sync with the build dependencies in docker/Dockerfile-dhvirtualenv.
 Build-Depends:
- debhelper (>= 10),
+ debhelper-compat (= 12),
  dh-virtualenv (>= 1.1),
  libsystemd-dev,
  libpq-dev,

debian/matrix-synapse.service

@@ -5,13 +5,17 @@ Description=Synapse Matrix homeserver
 Type=notify
 User=matrix-synapse
 WorkingDirectory=/var/lib/matrix-synapse
-EnvironmentFile=-/etc/default/matrix-synapse
 ExecStartPre=/opt/venvs/matrix-synapse/bin/python -m synapse.app.homeserver --config-path=/etc/matrix-synapse/homeserver.yaml --config-path=/etc/matrix-synapse/conf.d/ --generate-keys
 ExecStart=/opt/venvs/matrix-synapse/bin/python -m synapse.app.homeserver --config-path=/etc/matrix-synapse/homeserver.yaml --config-path=/etc/matrix-synapse/conf.d/
 ExecReload=/bin/kill -HUP $MAINPID
 Restart=always
 RestartSec=3
 SyslogIdentifier=matrix-synapse
 
+# The environment file is not shipped by default anymore and the below directive
+# is for backwards compatibility only. Please use your homeserver.yaml if
+# possible.
+EnvironmentFile=-/etc/default/matrix-synapse
+
 [Install]
 WantedBy=multi-user.target

debian/rules

@@ -6,15 +6,17 @@
 # assume we only have one package
 PACKAGE_NAME:=`dh_listpackages`
 
-override_dh_systemd_enable:
-	dh_systemd_enable --name=matrix-synapse
-
-override_dh_installinit:
-	dh_installinit --name=matrix-synapse
+override_dh_installsystemd:
+	dh_installsystemd --name=matrix-synapse
 
 # we don't really want to strip the symbols from our object files.
 override_dh_strip:
 
+# many libraries pulled from PyPI have allocatable sections after
+# non-allocatable ones on which dwz errors out. For those without the issue the
+# gains are only marginal
+override_dh_dwz:
+
 # dh_shlibdeps calls dpkg-shlibdeps, which finds all the binary files
 # (executables and shared libs) in the package, and looks for the shared
 # libraries that they depend on. It then adds a dependency on the package that