A few days ago, we released debhelper/12 and yesterday uploaded it to stretch-backports (as debhelper/12~bpo9+1). We deliberately released debhelper/12 so it would be included in buster for the people, who backport their packages to older releases via stable-backports. That said, we would like to remind people to please be careful with bumping the debhelper compat level at this point of the release cycle. We generally recommand you defer migrating to compat 12 until bullseye (to avoid having to revert that change in case you need an unblock for the buster release).
Upgrading to compat 12
If/when you upgrade the compat level, please consider using the recently added debhelper-compat (= 12) build-dependency form. It reduces redundancy, centralizes your debhelper relations to debian/control (replacing debian/compat) and avoids having you remember that you need a ~ in your build-dependency to support backports.
As usual, you can read about which behavioural changes are introduced by compat 12 in the debhelper(7) manpage. About one third of the changes are removing deprecated features and the rest are mostly about tweaking “minor” defaults. Though, please be careful around systemd unit files for two reasons:
- debhelper cleanly separates the handling of systemd unit files, so dh_installsystemd now 100% manages these while dh_installinit takes care of the sysvinit scripts. In particular, if you have something like dh_installinit –no-start then you almost certainly also want a dh_installsystemd –no-start if you have systemd unit shadowing the sysvinit file.
- Caveat for stretch-backports support: Due to the above, we need a versioned Pre-Depends on init-system-helpers. That version is unfortunately not available in stretch nor stretch-backports and therefore packages relying on this cannot be safely backported to stretch (but they will be backportable to buster).
If you target stretch-backports and ship services, we recommend you to stay with compat 11 for now.
General changes since stretch (i.e. 10.2.5 to 12):
The following are some of the changes that have been introduced in debhelper since the stretch release (available via stretch-backports):
- dh_missing was added to take over dh_install –list-missing/–fail-missing while reducing some of the issues that dh_install had with those options.
- debhelper now supports the meson+ninja and cmake+ninja build system.
- Improved or added cross-compilation support (via the dh_auto_* tools) for:
- meson build system
- cmake build system
- (“plain”) makefile system (parts only in compat 11+)
- qmake build system (qt5)
- Experimental support for cross-building for TARGET rather than HOST (for the about less than 5 source packages in total that might find this useful).
- Improved bulk performance in various parts of debhelper.
- Support for “nodoc” profile/build option plus the “terse” build option.
- Correctly handle systemd units with \x2d (escaped “-“) in their name.
- Rules-Requires-Root support when the field is set and dpkg-dev notifies debhelper that it supports the feature (requires dpkg-dev from Debian buster). Besides removing the need for (fake)root it can also remove about 3 invocations of debian/rules.
- Reduced dbgsym files via dh_dwz (use either manually, with dh –with dwz or dh + compat 12).
- Enable dh to skip more no-op commands including dh_auto_* and to a minor extend also even when dh is passed arguments that it should pass on to the underlying tools.
- Support for setting debhelper compat level via debhelper-compat (= X) build-dependency and load dh add-on sequences via dh-sequence-foo build-dependency (as an alternative to the original methods).
- Support for derivatives and custom/local builds using DH_EXTRA_ADDONS to enable derivative or custom add-ons for debhelper. Note: Packagers should keep using –with foo or the new dh-sequence-foo build-dependency – this interface is intended to enable a particular add-on without changing the package.
- Improved maintscript snippet ordering to ensure that service enable + start related snippets always run last in postinst (and first in prerm etc.) in the code inserted via the #DEBHELPER# token. This ensures that all other scripts (e.g. configuration file management via dh_ucf or the debian/maintscript file) is complete by the time the service (re)starts.
- Improved “rollback” handling of maintscripts generated by debhelper. Among other, debhelper autoscripts now handle cases like abort-deconfigure and abort-upgrade. In general, they are handled like configure and replays the setup to ensure that services are correctly running as expected.
- The autoscript snippet for loading systemd tmpfiles now simply uses the basename of the tmpfiles configuration, which enables the administrator to override the package provided tmpfiles configuration by placing their own in /etc/tmpfiles.d.
- The new dh_installinitramfs tool now installs maintainer provided initramfs hooks and generates autosnippets for all hooks installed in /usr/share/initramfs-tools/hooks. Enable via dh –with installinitramfs or dh + compat 12 or call it manually.
- The new dh_installsystemduser which manages system units per user rather than for the system. Enable via dh + compat 12 or call it manually.
The above is by no means complete and among other excludes many things that is introduced in compat 11 or compat 12.
Many thanks to the following people, who contributed to debhelper since stretch release with one or more patches (based on git log debian/10.2.5..debian/12 | git shortlog):
Adam Conrad, Américo Monteiro, Axel Beckert, Baptiste Jammet, Chris Lamb, Chris Leick, Christoph Biedl, Clément Hermann, Colin Watson, Daniele Nicolodi, Dmitry Shachnev, Fabian Grünbichler, Fabian Wolff, Felipe Sateler, Geoffrey Thomas, Helmut Grohne, Hideki Yamane, Iain Lane, Isaac Jurado, Jakub Wilk, Johannes Schauer, Josh Triplett, Juhani Numminen, Lisandro Damián Nicanor Pérez Meyer, Luca Boccassi, Mattia Rizzolo, Michael Biebl, Michael Stapelberg, Nicholas Guriev, Nicolas Boulenguez, Niels Thykier, Olly Betts, Paul Tagliamonte, Peter Pentchev, Roberto C. Sánchez, Steven Chamberlain, Sven Joachim, Ville Skyttä, gregor herrmann
Also, many thanks to the people reporting bugs, regressions and feature suggestions via the Debian BTS.