dh - debhelper command sequencer
] [debhelper options
runs a sequence of debhelper commands. The supported sequence
correspond to the targets of a debian/rules
file using dh
can override the command that is run
at any step in a sequence, by defining an override target.
To override dh_command
, add a target named
to the rules file. When it would normally
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.
Override targets can also be defined to run only when building architecture
dependent or architecture independent packages. Use targets with names like
. (Note that to use this
feature, you should Build-Depend on debhelper 8.9.7 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.
- --without addon
- The inverse of --with, disables using the given
addon. This option can be repeated more than once, or multiple addons to
disable can be listed, separated by commas.
- --list, -l
- List all available addons.
This can be used without a debian/compat file.
- Prints commands that would run for a given sequence, but
does not run them.
Note that dh normally skips running commands that it knows will do nothing.
With --no-act, the full list of commands in a sequence is printed.
Other options passed to dh
are passed on to each command it runs. This
can be used to set an option like -v
, as well
as for more specialised options.
To see what commands are included in a sequence, without actually doing
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_auto_configure -- --with-foo --disable-bar
Sometimes the automated dh_auto_configure(1)
can't guess what to do for a strange package. Here's how to avoid running
either and instead run your own commands.
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
Python tools are not run by dh by default, due to the continual change in that
area. (Before compatibility level v9, dh does run dh_pysupport
is how to use dh_python2
dh $@ --with python2
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
Here is an example of overriding where the dh_auto_*
the package's source, for a package where the source is located in a
dh $@ --sourcedirectory=src
And here is an example of how to tell the dh_auto_*
build in a subdirectory, which will be removed on clean
dh $@ --builddirectory=build
If your package can be built in parallel, please either use compat 10 or pass
to dh. Then dpkg-buildpackage -j
dh $@ --parallel
If your package cannot be built reliably while using multiple threads, please
to dh (or the relevant dh_auto_*
dh $@ --no-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:
A long build process for a separate documentation package can be separated out
using architecture independent overrides. These will be skipped when running
build-arch and binary-arch sequences.
$(MAKE) -C docs
# No tests needed for docs
$(MAKE) -C docs install
Adding to the example above, suppose you need to chmod a file, but only when
building the architecture dependent package, as it's not present when building
chmod 4755 debian/foo/usr/bin/foo
If you're curious about dh
's internals, here's how it works under the
In compat 10 (or later), dh
creates a stamp file
after the build step(s) are complete to
avoid re-running them. Inside an override target, dh_*
create a log file debian/package.debhelper.log
to keep track of which
packages the command(s) have been run for. These log files are then removed
once the override target is complete.
In compat 9 or earlier, each debhelper command will record when it's
successfully run in debian/package.debhelper.log
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 (in compat 9 or earlier), 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
, and --remaining
options can override
this behavior (though they were removed in compat 10).
A sequence can also run dependent targets in debian/rules. For example, the
"binary" sequence runs the "install" target.
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.
Commands in the build-indep
sequences are passed the -i
option to ensure they only work on
architecture independent packages, and commands in the build-arch
sequences are passed the -a
option to ensure they only work on architecture dependent packages.
The following options are deprecated. It's much better to use override targets
instead. They are not
available in compat 10.
- --until cmd
- Run commands in the sequence until and including
cmd, then stop.
- --before cmd
- Run commands in the sequence before cmd, then
- --after cmd
- Run commands in the sequence that come after
- Run all commands in the sequence that have yet to be
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 used.
This program is a part of debhelper.
Joey Hess <firstname.lastname@example.org>