DH(1) Debhelper DH(1)
dh - debhelper command sequencer
dh sequence [--with addon[,addon ...]] [--list] [--until cmd] [--before cmd] [--after cmd]
dh runs a sequence of debhelper commands. The supported sequences correspond to the
targets of a debian/rules file: build-arch, build-indep, build, clean, install-indep,
install-arch, install, binary-arch, binary-indep, and binary.
Commands in the build-indep, install-indep and binary-indep sequences are passed the -i
option to ensure they only work on architecture independent packages, and commands in the
build-arch, install-arch and binary-arch sequences are passed the -a option to ensure they
only work on architecture dependent packages.
If debian/rules contains a target with a name like override_dh_command, then when it would
normally run dh_command, dh will instead call that target. The override target can then
run the command with additional options, or run entirely different commands instead. See
examples below. (Note that to use this feature, you should Build-Depend on debhelper
7.0.50 or above.)
--with addon[,addon ...]
Add the debhelper commands specified by the given addon to appropriate places in the
sequence of commands that is run. This option can be repeated more than once, or
multiple addons can be listed, separated by commas. This is used when there is a
third-party package that provides debhelper commands. See the PROGRAMMING file for
documentation about the sequence addon interface.
The inverse of --with, disables using the given addon.
List all available addons.
Run commands in the sequence until and including cmd, then stop.
Run commands in the sequence before cmd, then stop.
Run commands in the sequence that come after cmd.
Run all commands in the sequence that have yet to be run.
Prints commands that would run for a given sequence, but does not run them.
All other options passed to dh are passed on to each command it runs. This can be used to
set an option like -v or -X or -N, as well as for more specialised options.
In the above options, cmd can be a full name of a debhelper command, or a substring. It'll
first search for a command in the sequence exactly matching the name, to avoid any
ambiguity. If there are multiple substring matches, the last one in the sequence will be
To see what commands are included in a sequence, without actually doing anything:
dh binary-arch --no-act
This is a very simple rules file, for packages where the default sequences of commands
work with no additional options.
Often you'll want to pass an option to a specific debhelper command. The easy way to do
with is by adding an override target for that command.
dh_installdocs README TODO
Sometimes the automated dh_auto_configure(1) and dh_auto_build(1) can't guess what to do
for a strange package. Here's how to avoid running either and instead run your own
Another common case is wanting to do something manually before or after a particular
debhelper command is run.
chmod 4755 debian/foo/usr/bin/foo
If your package is a Python package, dh will use dh_pysupport by default. This is how to
use dh_pycentral instead.
dh $@ --with python-central
If your package uses autotools and you want to freshen config.sub and config.guess with
newer versions from the autotools-dev package at build time, you can use some commands
provided in autotools-dev that automate it, like this.
dh $@ --with autotools_dev
Here is how to force use of Perl's Module::Build build system, which can be necessary if
debhelper wrongly detects that the package uses MakeMaker.
dh $@ --buildsystem=perl_build
To patch your package using quilt, you can tell dh to use quilt's dh sequence addons like
dh $@ --with quilt
Here is an example of overriding where the dh_auto_* commands find the package's source,
for a package where the source is located in a subdirectory.
dh $@ --sourcedirectory=src
And here is an example of how to tell the dh_auto_* commands to build in a subdirectory,
which will be removed on clean.
dh $@ --builddirectory=build
If your package can be built in parallel, you can support parallel building as follows.
Then dpkg-buildpackage -j will work.
dh $@ --parallel
Here is a way to prevent dh from running several commands that you don't want it to run,
by defining empty override targets for each command.
# Commands not to run:
override_dh_auto_test override_dh_compress override_dh_fixperms:
Sometimes, you may need to make an override target only run commands when a particular
package is being built. This can be accomplished using dh_listpackages(1) to test what is
being built. For example:
ifneq (,$(filter foo, $(shell dh_listpackages)))
chmod 4755 debian/foo/usr/bin/foo
Finally, remember that you are not limited to using override targets in the rules file
when using dh. You can also explicitly define any of the regular rules file targets when
it makes sense to do so. A common reason to do this is when your package needs different
build-arch and build-indep targets. For example, a package with a long document build
process can put it in build-indep.
Note that in the example above, dh will arrange for "debian/rules build" to call your
build-indep and build-arch targets. You do not need to explicitly define the dependencies
in the rules file when using dh with compatability level v9. This example would be more
complicated with earlier compatability levels.
If you're curious about dh's internals, here's how it works under the hood.
Each debhelper command will record when it's successfully run in
debian/package.debhelper.log. (Which dh_clean deletes.) So dh can tell which commands have
already been run, for which packages, and skip running those commands again.
Each time dh is run, it examines the log, and finds the last logged command that is in the
specified sequence. It then continues with the next command in the sequence. The --until,
--before, --after, and --remaining options can override this behavior.
A sequence can also run dependent targets in debian/rules. For example, the "binary"
sequence runs the "install" target.
dh sets environment variables listed by dpkg-buildflags, unless they are already set. It
supports DEB_BUILD_OPTIONS=noopt too.
dh uses the DH_INTERNAL_OPTIONS environment variable to pass information through to
debhelper commands that are run inside override targets. The contents (and indeed,
existence) of this environment variable, as the name might suggest, is subject to change
at any time.
This program is a part of debhelper.
Joey Hess <firstname.lastname@example.org>
8.9.0ubuntu2.1 2012-06-12 DH(1)