debhelper

debhelper - the debhelper tool suite

Debhelper is used to help you build a debian package. The philosophy behind debhelper is to provide a collection of small, simple, and easily understood tools that are used in debian/rules to automate various common aspects of building a package. This means less work for you, the packager. It also, to some degree means that these tools can be changed if debian policy changes, and packages that use them will require only a rebuild to comply with the new policy.

A typical debian/rules file that uses debhelper will call several debhelper commands in sequence. Debhelper commands are all named with a “dh_” prefix. Examples of rules files that use debhelper are in /usr/share/doc/debhelper/examples/

To create a new debian package using debhelper, you can just copy one of the sample rules files and edit it by hand. Or you can try the dh-make package, which contains a dh_make command that partially automates the process. For a more gentle introduction, the maint-guide debian package contains a tutorial about making your first package using debhelper.

Here is the complete list of available debhelper commands. See their man pages for additional documentation.

"dh_builddeb(1)" build debian packages

"dh_clean(1)" clean up package build directories

"dh_compress(1)" compress files and fix symlinks in package build directories

"dh_desktop(1)" Register .desktop files

"dh_fixperms(1)" fix permissions of files in package build directories

"dh_gconf(1)" generate GConf schema registration scripts

"dh_gencontrol(1)" generate and install control file

"dh_iconcache(1)" Updates the Icon Cache for icons in /usr/share/icons by calling dh_icons. This script is going to go away.

"dh_icons(1)" Update Freedesktop icon caches

"dh_install(1)" install files into package build directories

"dh_installcatalogs(1)" install and register \s-1SGML\s0 Catalogs

"dh_installchangelogs(1)" install changelogs into package build directories

"dh_installcron(1)" install cron scripts into etc/cron.*

"dh_installdeb(1)" install files into the \s-1DEBIAN\s0 directory

"dh_installdebconf(1)" install files used by debconf in package build directories

"dh_installdirs(1)" create subdirectories in package build directories

"dh_installdocs(1)" install documentation into package build directories

"dh_installemacsen(1)" register an emacs add on package

"dh_installexamples(1)" install example files into package build directories

"dh_installifupdown(1)" install if-up and if-down hooks

"dh_installinfo(1)" install and register info files

"dh_installinit(1)" install init scripts into package build directories

"dh_installlogcheck(1)" install logcheck rulefiles into etc/logcheck/

"dh_installlogrotate(1)" install logrotate config files

"dh_installman(1)" install man pages into package build directories

"dh_installmanpages(1)" old-style man page installer

"dh_installmenu(1)" install debian menu files into package build directories

"dh_installmime(1)" install mime files into package build directories

"dh_installmodules(1)" register modules with modutils

"dh_installpam(1)" install pam support files

"dh_installppp(1)" install ppp ip-up and ip-down files

"dh_installudev(1)" install udev rules files

"dh_installwm(1)" register a window manager

"dh_installxfonts(1)" register X fonts

"dh_link(1)" create symlinks in package build directories

"dh_listpackages(1)" list binary packages debhelper will act on

"dh_makeshlibs(1)" automatically create shlibs file

"dh_md5sums(1)" generate DEBIAN/md5sums file

"dh_movefiles(1)" move files out of debian/tmp into subpackages

"dh_perl(1)" calculates perl dependencies

"dh_python(1)" calculates python dependencies and adds postinst and prerm python scripts

"dh_scrollkeeper(1)" generate ScrollKeeper registration scripts

"dh_shlibdeps(1)" calculate shared library dependencies

"dh_strip(1)" strip executables, shared libraries, and some static libraries

"dh_suidregister(1)" obsolete suid registration program

"dh_testdir(1)" test directory before building debian package

"dh_testroot(1)" ensure that a package is built as root

"dh_testversion(1)" ensure that the correct version of debhelper is installed

"dh_undocumented(1)" obsolete undocumented.7 symlink program

"dh_usrlocal(1)" migrate usr/local directories to maintainer scripts

If a program's name starts with “dh_”, and the program is not on the above list, then it is not part of the debhelper package, but it should still work like the other programs described on this page.

Many debhelper commands make use of files in debian/ to control what they do. Besides the common debian/changelog and debian/control, which are in all packages, not just those using debhelper, some additional files can be used to configure the behavior of specific debhelper commands. These files are typically named debian/package.foo (where “package” of course, is replaced with the package that is being acted on).

For example, dh_installdocs uses files named debian/package.docs to list the documentation files it will install. See the man pages of individual commands for details about the names and formats of the files they use. Generally, these files will list files to act on, one file per line. Some programs in debhelper use pairs of files and destinations or slightly more complicated formats.

Note that if a package is the first (or only) binary package listed in debian/control, debhelper will use debian/foo if no debian/package.foo file can be found.

In some rare cases, you may want to have different versions of these files for different architectures. If files named debian/package.foo.arch exist, where “arch” is the same as the output of “dpkg-architecture -qDEB_HOST_ARCH”, then they will be used in preference to other, more general files.

In many cases, these config files are used to specify various types of files. Documentation or example files to install, files to move, and so on. When appropriate, in cases like these, you can use standard shell wildcard characters ('?' and '*' and '[..]' character classes) in the files.

You can also put comments in these files; lines beginning with “#” are ignored.

The following command line options are supported by all debhelper programs.

"-v, Verbose mode: show all commands that modify the package build directory.

"--no-act" Do not really do anything. If used with -v, the result is that the command will output what it would have done.

"-a, Act on all architecture dependent packages.

"-i, Act on all architecture independent packages.

"-ppackage, Act on the package named “package”. This option may be specified multiple times to make debhelper operate on a given set of packages.

"-s, This is a smarter version of the -a flag, that is used in some rare circumstances. It understands that if the control file lists “Architecture: i386” for the package, the package should not be acted on on other architectures. So this flag makes the command act on all “Architecture: any” packages, as well as on any packages that have the current architecture explicitly specified. Contrast to the -a flag, which makes the command work on all packages that are not architecture independent.

"-Npackage, Do not act on the specified package even if an -a, -i, or -p option lists the package as one that should be acted on.

"-Ptmpdir, Use “tmpdir” for package build directory. The default is debian/<package>

"--mainpackage=package" This little-used option changes the package which debhelper considers the “main package”, that is, the first one listed in debian/control, and the one for which debian/foo files can be used instead of the usual debian/package.foo files.

The following command line options are supported by some debhelper programs. See the man page of each program for a complete explanation of what each option does.

"-n" Do not modify postinst/postrm/etc scripts.

"-Xitem, Exclude an item from processing. This option may be used multiple times, to exclude more than one thing.

"-A, Makes files or other items that are specified on the command line take effect in \s-1ALL\s0 packages acted on, not just the first.

If your source package generates more than one binary package, debhelper programs will default to acting on all binary packages when run. If your source package happens to generate one architecture dependent package, and another architecture independent package, this is not the correct behavior, because you need to generate the architecture dependent packages in the binary-arch debian/rules target, and the architecture independent packages in the binary-indep debian/rules target.

To facilitate this, as well as give you more control over which packages are acted on by debhelper programs, all debhelper programs accept the -a, -i, -p, and -s parameters. These parameters are cumulative. If none are given, debhelper programs default to acting on all packages listed in the control file.

See /usr/share/doc/debhelper/examples/rules.multi for an example of how to use this in a package that generates multiple binary packages.

Some debhelper commands will automatically generate parts of debian maintainer scripts. If you want these automatically generated things included in your existing debian maintainer scripts, then you need to add “#DEBHELPER#” to your scripts, in the place the code should be added. “#DEBHELPER#” will be replaced by any auto-generated code when you run dh_installdeb.

If a script does not exist at all and debhelper needs to add something to it, then debhelper will create the complete script.

All debhelper commands that automatically generate code in this way let it be disabled by the -n parameter (see above).

Note that the inserted code will be shell code, so you cannot directly use it in a perl script. If you would like to embed it into a perl script, here is one way to do that (note that I made sure that CW$1, CW$2, etc are set with the set command):

my $temp="set -e\nset -- @ARGV\n" . << 'EOF'; #DEBHELPER# EOF system ($temp) / 256 == 0 or die "Problem with debhelper scripts: $!";

Some debhelper commands may make the generated package need to depend on some other packages. For example, if you use dh_installdebconf(1), your package will generally need to depend on debconf. Or if you use dh_installxfonts(1), your package will generally need to depend on a particular version of xutils. Keeping track of these miscellaneous dependencies can be annoying since they are dependant on how debhelper does things, so debhelper offers a way to automate it.

All commands of this type, besides documenting what dependencies may be needed on their man pages, will automatically generate a substvar called ${misc:Depends}. If you put that token into your debian/control file, it will be expanded to the dependencies debhelper figures you need.

This is entirely independent of the standard ${shlibs:Depends} generated by dh_makeshlibs(1), and the ${perl:Depends} generated by dh_perl(1). You can choose not to use any of these, if debhelper's guesses don't match reality.

By default, all debhelper programs assume that the temporary directory used for assembling the tree of files in a package is debian/<package>.

Sometimes, you might want to use some other temporary directory. This is supported by the -P flag. For example, “dh_installdocs -Pdebian/tmp”, will use debian/tmp as the temporary directory. Note that if you use -P, the debhelper programs can only be acting on a single package at a time. So if you have a package that builds many binary packages, you will need to also use the -p flag to specify which binary package the debhelper program will act on.

From time to time, major non-backwards-compatible changes need to be made to debhelper, to keep it clean and well-designed as needs change and its author gains more experience. To prevent such major changes from breaking existing packages, the concept of debhelper compatibility levels was introduced. You tell debhelper which compatibility level it should use, and it modifies its behavior in various ways.

Tell debhelper what compatibility level to use by writing a number to debian/compat. For example, to turn on V5 mode:

% echo 5 > debian/compat

Unless otherwise indicated, all debhelper documentation assumes that you are using the most recent compatibility level, and in most cases does not indicate if the behavior is different in an earlier compatibility level, so if you are not using the most recent compatibility level, you're advised to read below for notes about what is different in earlier compatibility levels.

These are the available compatibility levels:

"V1" This is the original debhelper compatibility level, and so it is the default one. In this mode, debhelper will use debian/tmp as the package tree directory for the first binary package listed in the control file, while using debian/<package> for all other packages listed in the control file. This mode is deprecated.

"V2" In this mode, debhelper will consistently use debian/<package> as the package tree directory for every package that is built. This mode is deprecated.

"V3" This mode works like V2, with the following additions:

"-" Debhelper config files support globbing via * and ?, when appropriate. To turn this off and use those characters raw, just prefix with a backslash.

"-" dh_makeshlibs makes the postinst and postrm scripts call ldconfig.

"-" Every file in etc/ is automatically flagged as a conffile by dh_installdeb.

"V4" Changes from V3 are:

"-" dh_makeshlibs -V will not include the debian part of the version number in the generated dependency line in the shlibs file.

"-" You are encouraged to put the new ${misc:Depends} into debian/control to supplement the ${shlibs:Depends} field.

"-" dh_fixperms will make all files in bin/ directories and in etc/init.d executable.

"-" dh_link will correct existing links to conform with policy.

"V5" This is the recommended mode of operation. It does everything V4 does, plus:

"-" Comments are ignored in debhelper config files.

"-" dh_strip --dbg-package now specifies the name of a package to put debugging symbols in, not the packages to take the symbols from.

"-" dh_installdocs skips installing empty files.

"-" dh_install errors out if wildcards expand to nothing.

"V6" This mode is still under development. Currently it has these differences compared to V5:

"-" Commands that generate maintainer script fragements will order the fragements in reverse order for the prerm and postrm scripts.

"-" dh_installwm will install a slave manpage link for x-window-manager.1.gz, if it sees the man page in usr/share/man/man1 in the package build directory.

"-" dh_builddeb did not previously delete everything matching \s-1DH_ALWAYS_EXCLUDE\s0, if it was set to a list of things to exclude, such as “\s-1CVS:\s0.svn”. Now it does.

"-" dh_installman allows overwriting existing man pages in the package build directory. In previous compatability levels it silently refuses to do this.

Sometimes it is useful to make a package not contain a /usr/share/doc/package directory at all, instead placing just a dangling symlink in the binary package, that points to some other doc directory. Policy says this is ok if your package depends on the package whose doc directory it uses. To accomplish this, just don't tell debhelper to install any documentation files into the package, and use dh_link to set up the symlink (or do it by hand), and debhelper should do the right thing: notice it is a dangling symlink and not try to install a copyright file or changelog.

Debhelper includes support for udebs. To create a udeb with debhelper, add “XC-Package-Type: udeb” to the package's stanza in debian/control, and build-depend on debhelper (>= 4.2). Debhelper will try to create udebs that comply with debian-installer policy, by making the generated package files end in “.udeb”, not installing any documentation into a udeb, skipping over preinst, postrm, prerm, and config scripts, etc.

In general, if any debhelper program needs a directory to exist under debian/, it will create it. I haven't bothered to document this in all the man pages, but for example, dh_installdeb knows to make debian/<package>/DEBIAN/ before trying to put files there, dh_installmenu knows you need a debian/<package>/usr/share/menu/ before installing the menu files, etc. Once your package uses debhelper to build, be sure to add debhelper to your Build-Depends line in debian/control. You should build-depend on a version of debhelper equal to (or greater than) the debhelper compatibility level your package uses. So if your package used compatibility level 5: Build-Depends: debhelper (>= 5)

"\s-1DH_VERBOSE\s0" Set to 1 to enable verbose mode. Debhelper will output every command it runs that modifies files on the build system.

"\s-1DH_COMPAT\s0" Temporarily specifies what compatibility level debhelper should run at, overriding any value in debian/compat.

"\s-1DH_NO_ACT\s0" Set to 1 to enable no-act mode.

"\s-1DH_OPTIONS\s0" Anything in this variable will be prepended to the command line arguments of all debhelper commands. This is useful in some situations, for example, if you need to pass -p to all debhelper commands that will be run. One good way to set \s-1DH_OPTIONS\s0 is by using “Target-specific Variable Values” in your debian/rules file. See the make documentation for details on doing this.

"\s-1DH_ALWAYS_EXCLUDE\s0" If set, this adds the value the variable is set to to the -X options of all commands that support the -X option. Moreover, dh_builddeb will rm -rf anything that matches the value in your package build tree. This can be useful if you are doing a build from a \s-1CVS\s0 source tree, in which case setting DH_ALWAYS_EXCLUDE=CVS will prevent any \s-1CVS\s0 directories from sneaking into the package you build. Or, if a package has a source tarball that (unwisely) includes \s-1CVS\s0 directories, you might want to export DH_ALWAYS_EXCLUDE=CVS in debian/rules, to make it take effect wherever your package is built. Multiple things to exclude can be separated with colons, as in DH_ALWAYS_EXCLUDE=CVS:.svn

"/usr/share/doc/debhelper/examples/" A set of example debian/rules files that use debhelper.

"<http://kitenet.net/~joey/code/debhelper/>" Debhelper web site.

Joey Hess <joeyh@debian.org>