dh
debhelper command sequencer
Synopsis
dh
sequence [--with
addon[,addon ...]]
[--list]
[debhelper options]
add an example, a script, a trick and tips
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
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.
#!/usr/bin/make -f
dh $@ --with autotools_dev
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.) 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, you can support
parallel building as follows. Then dpkg-buildpackage -j
will work.
#!/usr/bin/make -f
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.
#!/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
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.
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.
--no-act
Prints commands that would run
for a given sequence, but does not run them.
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.
deprecated options
The following options are deprecated. It’s much better to use
override targets instead.
--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.
internals
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 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.
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. (Note that to use this feature, you should
Build-Depend on debhelper 7.0.50 or above.)
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.)
see also
debhelper
This program is
a part of debhelper.
author
Joey Hess
<joeyh[:at:]debian[:dot:]org>