Provided by: debhelper_11.1.6ubuntu2_all 
NAME
dh - debhelper command sequencer
SYNOPSIS
dh sequence [--with addon[,addon ...]] [--list] [debhelper options]
DESCRIPTION
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.
OVERRIDE TARGETS
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 override_dh_command to the rules file. 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.
Override targets can also be defined to run only when building architecture dependent or architecture
independent packages. Use targets with names like override_dh_command-arch and
override_dh_command-indep. (Note that to use this feature, you should Build-Depend on debhelper 8.9.7 or
above.)
OPTIONS
--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.
When called only with this option, dh can be called from any directory (i.e. it does not need access
to files from a source package).
--no-act
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 or -X or -N, as well as for more specialised options.
EXAMPLES
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.
#!/usr/bin/make -f
%:
dh $@
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.
#!/usr/bin/make -f
%:
dh $@
override_dh_strip:
dh_strip -Xfoo
override_dh_auto_configure:
dh_auto_configure -- --with-foo --disable-bar
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 commands.
#!/usr/bin/make -f
%:
dh $@
override_dh_auto_configure:
./mondoconfig
override_dh_auto_build:
make universe-explode-in-delight
Another common case is wanting to do something manually before or after a particular debhelper command is
run.
#!/usr/bin/make -f
%:
dh $@
override_dh_fixperms:
dh_fixperms
chmod 4755 debian/foo/usr/bin/foo
Python tools are not run by dh by default, due to the continual change in that area. Here is how to use
dh_python2.
#!/usr/bin/make -f
%:
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.
#!/usr/bin/make -f
%:
dh $@ --buildsystem=perl_build
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.
#!/usr/bin/make -f
%:
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.
#!/usr/bin/make -f
%:
dh $@ --builddirectory=build
If your package can be built in parallel, please either use compat 10 or pass --parallel to dh. Then
dpkg-buildpackage -j will work.
#!/usr/bin/make -f
%:
dh $@ --parallel
If your package cannot be built reliably while using multiple threads, please pass --no-parallel to dh
(or the relevant dh_auto_* command):
#!/usr/bin/make -f
%:
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.
#!/usr/bin/make -f
%:
dh $@
# 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.
#!/usr/bin/make -f
%:
dh $@
override_dh_auto_build-indep:
$(MAKE) -C docs
# No tests needed for docs
override_dh_auto_test-indep:
override_dh_auto_install-indep:
$(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 only documentation.
override_dh_fixperms-arch:
dh_fixperms
chmod 4755 debian/foo/usr/bin/foo
INTERNALS
If you're curious about dh's internals, here's how it works under the hood.
In compat 10 (or later), dh creates a stamp file debian/debhelper-build-stamp after the build step(s) are
complete to avoid re-running them. It is possible to avoid the stamp file by passing
--without=build-stamp to dh. This makes "no clean" builds behave more like what some people expect at
the expense of possibly running the build and test twice (the second time as root or under fakeroot(1)).
Inside an override target, dh_* commands will 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. (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 (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,
--before, --after, 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.
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.
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.
DEPRECATED OPTIONS
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 stop.
--after cmd
Run commands in the sequence that come after cmd.
--remaining
Run all commands in the sequence that have yet to be run.
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.
SEE ALSO
debhelper(7)
This program is a part of debhelper.
AUTHOR
Joey Hess <joeyh@debian.org>
11.1.6ubuntu2 2018-05-10 DH(1)