jammy (7) debhelper.7.gz

Provided by: debhelper_13.6ubuntu1_all bug

NAME

       debhelper - the debhelper tool suite

SYNOPSIS

       dh_* [-v] [-a] [-i] [--no-act] [-ppackage] [-Npackage] [-Ptmpdir]

DESCRIPTION

       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, or use
       dh(1) to automate this process. 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.

       Except where the tool explicitly denotes otherwise, all of the debhelper tools assume that they run from
       the root directory of an unpacked source package.  This is so they can locate find files like
       debian/control when needed.

DEBHELPER COMMANDS

       Here is the list of debhelper commands you can use. See their man pages for additional documentation.

       dh_assistant(1)
           tool for supporting debhelper tools and provide introspection

       dh_auto_build(1)
           automatically builds a package

       dh_auto_clean(1)
           automatically cleans up after a build

       dh_auto_configure(1)
           automatically configure a package prior to building

       dh_auto_install(1)
           automatically runs make install or similar

       dh_auto_test(1)
           automatically runs a package's test suites

       dh_bugfiles(1)
           install bug reporting customization files into package build directories

       dh_builddeb(1)
           build Debian binary packages

       dh_clean(1)
           clean up package build directories

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

       dh_dwz(1)
           optimize DWARF debug information in ELF binaries via dwz

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

       dh_gencontrol(1)
           generate and install control file

       dh_icons(1)
           Update caches of Freedesktop icons

       dh_install(1)
           install files into package build directories

       dh_installalternatives(1)
           install declarative alternative rules

       dh_installcatalogs(1)
           install and register SGML 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 DEBIAN 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_installgsettings(1)
           install GSettings overrides and set dependencies

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

       dh_installinfo(1)
           install info files

       dh_installinit(1)
           install service init files into package build directories

       dh_installinitramfs(1)
           install initramfs hooks and setup maintscripts

       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_installmenu(1)
           install Debian menu files into package build directories

       dh_installmime(1)
           install mime files into package build directories

       dh_installmodules(1)
           register kernel modules

       dh_installpam(1)
           install pam support files

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

       dh_installsystemd(1)
           install systemd unit files

       dh_installsystemduser(1)
           install systemd unit files

       dh_installsysusers(1)
           install and integrates systemd sysusers files

       dh_installtmpfiles(1)
           install tmpfiles.d configuration 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_lintian(1)
           install lintian override files into package build directories

       dh_listpackages(1)
           list binary packages debhelper will act on

       dh_makeshlibs(1)
           automatically create shlibs file and call dpkg-gensymbols

       dh_md5sums(1)
           generate DEBIAN/md5sums file

       dh_missing(1)
           check for missing files

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

       dh_perl(1)
           calculates Perl dependencies and cleans up after MakeMaker

       dh_prep(1)
           perform cleanups in preparation for building a binary package

       dh_shlibdeps(1)
           calculate shared library dependencies

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

       dh_systemd_enable(1)
           enable/disable systemd unit files

       dh_systemd_start(1)
           start/stop/restart systemd unit files

       dh_testdir(1)
           test directory before building Debian package

       dh_testroot(1)
           ensure that a package is built with necessary level of root permissions

       dh_ucf(1)
           register configuration files with ucf

       dh_update_autotools_config(1)
           Update autotools config files

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

   Deprecated Commands
       A few debhelper commands are deprecated and should not be used.

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

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

DEBHELPER CONFIG FILES

       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 for the first (or only) binary package listed in debian/control, debhelper will use debian/foo when
       there's no debian/package.foo file.  However, it is often a good idea to keep the package. prefix as it
       is more explicit.  The primary exception to this are files that debhelper by default installs in every
       binary package when it does not have a package prefix (such as debian/copyright or debian/changelog).

       In some rare cases, you may want to have different versions of these files for different architectures or
       OSes. If files named debian/package.foo.ARCH or debian/package.foo.OS exist, where ARCH and OS are the
       same as the output of "dpkg-architecture -qDEB_HOST_ARCH" / "dpkg-architecture -qDEB_HOST_ARCH_OS", then
       they will be used in preference to other, more general files.

       Mostly, these config files are used to specify lists of 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 syntax of these files is intentionally kept very simple to make them easy to read, understand, and
       modify.

   Substitutions in debhelper config files
       In compatibility level 13 and later, it is possible to use simple substitutions in debhelper config files
       for the following tools:

       •   dh_clean

       •   dh_install

       •   dh_installcatalogs

       •   dh_installdeb

       •   dh_installdirs

       •   dh_installdocs

       •   dh_installexamples

       •   dh_installinfo

       •   dh_installman

       •   dh_installwm

       •   dh_link

       •   dh_missing

       •   dh_ucf

       All substitution variables are of the form ${foo} and the braces are mandatory.  Variable names are case-
       sensitive and consist of alphanumerics (a-zA-Z0-9), hyphens (-), underscores (_), and colons (:).  The
       first character must be an alphanumeric.

       If you need a literal dollar sign that cannot trigger a substitution, you can either use the ${Dollar}
       substitution or the sequence ${}.

       The following expansions are available:

       DEB_HOST_*, DEB_BUILD_*, DEB_TARGET_*
           Expands to the relevant dpkg-architecture(1) value (similar to dpkg-architecture -qVARIABLE_HERE).

           When in doubt, the DEB_HOST_* variant is the one that will work both for native and cross builds.

           For performance reasons, debhelper will attempt to resolve these names from the environment first
           before consulting dpkg-architecture(1).  This is mostly mentioned for completeness as it will not
           matter for most cases.

       Dollar
           Expands to a single literal $-symbol.  This symbol will never be considered part of a substitution
           variable.  That is:

              # Triggers an error
              ${NO_SUCH_TOKEN}
              # Expands to the literal value "${NO_SUCH_TOKEN}"
              ${Dollar}{NO_SUCH_TOKEN}

           This variable equivalent to the sequence ${} and the two can be used interchangeably.

       Newline, Space, Tab
           Expands to a single ASCII newline, space and tab respectively.

           This can be useful if you need to include a literal whitespace character (e.g. space) where it would
           otherwise be stripped or used as a separator.

       env:NAME
           Expands to the environment variable NAME.  The environment variable must be set (but can be set to
           the empty string).

       Note that all variables must expand to a defined value.  As an example, if debhelper sees ${env:FOO},
       then it will insist that the environment variable FOO is set (it can be set to the empty string).

       Substitution limits

       To avoid infinite loops and resource exhaustion, debhelper will stop with an error if the text contains
       many substitution variables (50) or they expand beyond a certain size (4096 characters or 3x length of
       the original input - whichever is bigger).

   Executable debhelper config files
       If you need additional flexibility, many of the debhelper tools (e.g. dh_install(1)) support executing a
       config file as a script.

       To use this feature, simply mark the config file as executable (e.g. chmod +x debian/package.install) and
       the tool will attempt to execute it and use the output of the script.  In many cases, you can use
       dh-exec(1) as interpreter of the config file to retain most of the original syntax while getting the
       additional flexibility you need.

       When using executable debhelper config files, please be aware of the following:

       •   The executable config file must exit with success (i.e. its return code should indicate success).

       •   In compatibility level 13+, the output will be subject to substitutions (see "Substitutions in
           debhelper config files") where the tool support these.  Remember to be careful if your generator also
           provides substitutions as this can cause unnecessary confusion.

           Otherwise, the output will be used exactly as-is.  Notably, debhelper will not expand wildcards or
           strip comments or strip whitespace in the output.

       If you need the package to build on a file system where you cannot disable the executable bit, then you
       can use dh-exec(1) and its strip-output script.

SHARED DEBHELPER OPTIONS

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

       -v, --verbose
           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, --arch
           Act on architecture dependent packages that should be built for the DEB_HOST_ARCH architecture.

       -i, --indep
           Act on all architecture independent packages.

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

       -s, --same-arch
           Deprecated alias of -a.

           This option is removed in compat 12.

       -Npackage, --no-package=package
           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.

       --remaining-packages
           Do not act on the packages which have already been acted on by this debhelper command earlier (i.e.
           if the command is present in the package debhelper log).  For example, if you need to call the
           command with special options only for a couple of binary packages, pass this option to the last call
           of the command to process the rest of packages with default settings.

       -Ptmpdir, --tmpdir=tmpdir
           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.

       -O=option|bundle
           This is used by dh(1) when passing user-specified options to all the commands it runs. If the command
           supports the specified option or option bundle, it will take effect. If the command does not support
           the option (or any part of an option bundle), it will be ignored.

COMMON DEBHELPER OPTIONS

       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=item
           Exclude an item from processing. This option may be used multiple times, to exclude more than one
           thing. The item is typically part of a filename, and any file containing the specified text will be
           excluded.

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

BUILD SYSTEM OPTIONS

       The following command line options are supported by all of the dh_auto_* debhelper programs. These
       programs support a variety of build systems, and normally heuristically determine which to use, and how
       to use them.  You can use these command line options to override the default behavior.  Typically these
       are passed to dh(1), which then passes them to all the dh_auto_* programs.

       -Sbuildsystem, --buildsystem=buildsystem
           Force use of the specified buildsystem, instead of trying to auto-select one which might be
           applicable for the package.

           Pass none as buildsystem to disable auto-selection.

       -Ddirectory, --sourcedir=directory, --sourcedirectory=directory
           Assume that the original package source tree is at the specified directory rather than the top level
           directory of the Debian source package tree.

           Warning: The --sourcedir variant matches a similar named option in dh_install and dh_missing (etc.)
           for historical reasons.  While they have a similar name, they have very distinct purposes and in some
           cases it can cause errors when this variant is passed to dh (when then passes it on to all tools).

       -B[directory], --builddir[=directory], --builddirectory[=directory]
           Enable out of source building and use the specified directory as the build directory. If directory
           parameter is omitted, a default build directory will be chosen.

           If this option is not specified, building will be done in source by default unless the build system
           requires or prefers out of source tree building.  In such a case, the default build directory will be
           used even if --builddirectory is not specified.

           If the build system prefers out of source tree building but still allows in source building, the
           latter can be re-enabled by passing a build directory path that is the same as the source directory
           path.

       --parallel, --no-parallel
           Control whether parallel builds should be used if underlying build system supports them.  The number
           of parallel jobs is controlled by the DEB_BUILD_OPTIONS environment variable ("Debian Policy, section
           4.9.1") at build time. It might also be subject to a build system specific limit.

           If neither option is specified, debhelper currently defaults to --parallel in compat 10 (or later)
           and --no-parallel otherwise.

           As an optimization, dh will try to avoid passing these options to subprocesses, if they are
           unnecessary and the only options passed.  Notably this happens when DEB_BUILD_OPTIONS does not have a
           parallel parameter (or its value is 1).

       --max-parallel=maximum
           This option implies --parallel and allows further limiting the number of jobs that can be used in a
           parallel build. If the package build is known to only work with certain levels of concurrency, you
           can set this to the maximum level that is known to work, or that you wish to support.

           Notably, setting the maximum to 1 is effectively the same as using --no-parallel.

       --reload-all-buildenv-variables
           By default, dh(1) will compute several environment (e.g. by using dpkg-buildflags(1)) and cache them
           to avoid having all dh_auto_* tool recompute them.

           When passing this option, the concrete dh_auto_* tool will ignore the cache from dh(1) and retrigger
           a rebuild of these variables.  This is useful in the very rare case where the package need to do
           multiple builds but with different ...FLAGS options.  A concrete example would be needing to change
           the -O parameter in CFLAGS in the second build:

               export DEB_CFLAGS_MAINT_APPEND=-O3

               %:
                   dh $@

               override_dh_auto_configure:
                   dh_auto_configure -Bbuild-deb ...
                   DEB_CFLAGS_MAINT_APPEND=-Os dh_auto_configure \
                      --reload-all-buildenv-variables -Bbuild-udeb ...

           Without --reload-all-buildenv-variables in the second call to dh_auto_configure(1), the change in
           DEB_CFLAGS_MAINT_APPEND would be ignored as dh_auto_configure(1) would use the cached value of CFLAGS
           set by dh(1).

           This option is only available with debhelper (>= 12.7~) when the package uses compatibility level 9
           or later.

       --list, -l
           List all build systems supported by debhelper on this system. The list includes both default and
           third party build systems (marked as such). Also shows which build system would be automatically
           selected, or which one is manually specified with the --buildsystem option.

COMPATIBILITY LEVELS

       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 must
       tell debhelper which compatibility level it should use, and it modifies its behavior in various ways.

       In current debhelper, you can specify the compatibility level in debian/control by adding a Build-Depends
       on the debhelper-compat package.  For example, to use v13 mode, ensure debian/control has:

         Build-Depends: debhelper-compat (= 13)

       This also serves as an appropriate versioned build dependency on a sufficient version of the debhelper
       package, so you do not need to specify a separate versioned build dependency on the debhelper package
       unless you need a specific point release of debhelper (such as for the introduction of a new feature or
       bugfix within a compatibility level).

       Note that debhelper does not provide debhelper-compat for experimental or beta compatibility levels;
       packages experimenting with those compatibility levels should use debian/compat or DH_COMPAT.

       Prior versions of debhelper required specifying the compatibility level in the file debian/compat, and
       current debhelper still supports this for backward compatibility, though a package may not specify a
       compatibility level via multiple methods at once. To use this method, debian/compat should contain the
       compatibility level as a single number, and no other content. If you specify the compatibility level by
       this method, your package will also need a versioned build dependency on a version of the debhelper
       package equal to (or greater than) the compatibility level your package uses. So, if you specify
       compatibility level 13 in debian/compat, ensure debian/control has:

         Build-Depends: debhelper (>= 13~)

       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.

   Supported compatibility levels
       These are the available compatibility levels:

       v7  This mode is deprecated.

           This is the lowest supported compatibility level.

           If you are upgrading from an earlier compatibility level, please review debhelper-obsolete-compat(7).

       v8  Changes from v7 are:

           -       Commands will fail rather than warning when they are passed unknown options.

           -       dh_makeshlibs will run dpkg-gensymbols on all shared libraries that it generates shlibs files
                   for. So -X can be used to exclude libraries.  Also, libraries in unusual locations that dpkg-
                   gensymbols would not have processed before will be passed to it, a behavior change that can
                   cause some packages to fail to build.

           -       dh requires the sequence to run be specified as the first parameter, and any switches come
                   after it. Ie, use "dh $@ --foo", not "dh --foo $@".

           -       dh_auto_* prefer to use Perl's Module::Build in preference to Makefile.PL.

           This mode is deprecated.

       v9  Changes from v8 are:

           -       Multiarch support. In particular, dh_auto_configure passes multiarch directories to autoconf
                   in --libdir and --libexecdir.

           -       dh is aware of the usual dependencies between targets in debian/rules.  So, "dh binary" will
                   run any build, build-arch, build-indep, install, etc targets that exist in the rules file.
                   There's no need to define an explicit binary target with explicit dependencies on the other
                   targets.

           -       dh_strip compresses debugging symbol files to reduce the installed size of -dbg packages.

           -       dh_auto_configure does not include the source package name in --libexecdir when using
                   autoconf.

           -       dh does not default to enabling --with=python-support

                   (Obsolete: As the dh_pysupport tool was removed from Debian stretch.  Since debhelper/10.3,
                   dh no longer enables this sequence add-on regardless of compat level)

           -       All of the dh_auto_* debhelper programs and dh set environment variables listed by dpkg-
                   buildflags, unless they are already set.

           -       dh_auto_configure passes dpkg-buildflags CFLAGS, CPPFLAGS, and LDFLAGS to perl Makefile.PL
                   and Build.PL

           -       dh_strip puts separated debug symbols in a location based on their build-id.

           -       Executable debhelper config files are run and their output used as the configuration.

           This mode is deprecated.

       v10 Changes from v9 are:

           -       dh_installinit will no longer install a file named debian/package as an init script.

           -       dh_installdocs will error out if it detects links created with --link-doc between packages of
                   architecture "all" and non-"all" as it breaks binNMUs.

           -       dh_installdeb no longer installs a maintainer-provided debian/package.shlibs file.  This is
                   now done by dh_makeshlibs instead.

           -       dh_installwm refuses to create a broken package if no man page can be found (required to
                   register for the x-window-manager alternative).

           -       Debhelper will default to --parallel for all buildsystems that support parallel building.
                   This can be disabled by using either --no-parallel or passing --max-parallel with a value of
                   1.

           -       The dh command will not accept any of the deprecated "manual sequence control" parameters
                   (--before, --after, etc.).  Please use override targets instead.

                   Retroactively applied to earlier compat levels: dh no longer accepts any of these since
                   debhelper/12.4.

           -       The dh command will no longer use log files to track which commands have been run.  The dh
                   command still keeps track of whether it already ran the "build" sequence and skip it if it
                   did.

                   The main effects of this are:

                   -   With this, it is now easier to debug the install or/and binary sequences because they can
                       now trivially be re-run (without having to do a full "clean and rebuild" cycle)

                   -   The main caveat is that dh_* now only keeps track of what happened in a single override
                       target.  When all the calls to a given dh_cmd command happens in the same override target
                       everything will work as before.

                       Example of where it can go wrong:

                         override_dh_foo:
                           dh_foo -pmy-pkg

                         override_dh_bar:
                           dh_bar
                           dh_foo --remaining

                       In this case, the call to dh_foo --remaining will also include my-pkg, since dh_foo
                       -pmy-pkg was run in a separate override target.  This issue is not limited to
                       --remaining, but also includes -a, -i, etc.

           -       The dh_installdeb command now shell-escapes the lines in the maintscript config file.  This
                   was the original intent but it did not work properly and packages have begun to rely on the
                   incomplete shell escaping (e.g. quoting file names).

           -       The dh_installinit command now defaults to --restart-after-upgrade.  For packages needing the
                   previous behaviour, please use --no-restart-after-upgrade.

           -       The autoreconf sequence is now enabled by default.  Please pass --without autoreconf to dh if
                   this is not desirable for a given package

           -       The systemd sequence is now enabled by default.  Please pass --without systemd to dh if this
                   is not desirable for a given package.

           -       Retroactively removed: dh no longer creates the package build directory when skipping running
                   debhelper commands. This will not affect packages that only build with debhelper commands,
                   but it may expose bugs in commands not included in debhelper.

                   This compatibility feature had a bug since its inception in debhelper/9.20130516 that made it
                   fail to apply in compat 9 and earlier.  As there has been no reports of issues caused by this
                   bug in those ~5 years, this item have been removed rather than fixed.

       v11 This mode is discouraged.

           The compat 11 is discouraged for new packages as it suffers from feature interaction between
           dh_installinit and dh_installsystemd causing services to not run correctly in some cases.  Please
           consider using compatibility mode 10 or 12 instead.  More details about the issue are available in
           Debian#887904 and <https://lists.debian.org/debian-release/2019/04/msg01442.html>.

           Changes from v10 are:

           -       dh_installinit no longer installs service or tmpfile files, nor generates maintainer scripts
                   for those files.  Please use the new dh_installsystemd helper.

           -       The dh_systemd_enable and dh_systemd_start helpers have been replaced by the new
                   dh_installsystemd helper.  For the same reason, the systemd sequence for dh has also been
                   removed.  If you need to disable the dh_installsystemd helper tool, please use an empty
                   override target.

                   Please note that the dh_installsystemd tool has a slightly different behaviour in some cases
                   (e.g. when using the --name parameter).

           -       dh_installdirs no longer creates debian/package directories unless explicitly requested (or
                   it has to create a subdirectory in it).

                   The vast majority of all packages will be unaffected by this change.

           -       The makefile buildsystem now passes INSTALL="install --strip-program=true" to make(1).
                   Derivative buildsystems (e.g. configure or cmake) are unaffected by this change.

           -       The autoconf buildsystem now passes --runstatedir=/run to ./configure.

           -       The cmake buildsystem now passes -DCMAKE_INSTALL_RUNSTATEDIR=/run to cmake(1).

           -       dh_installman will now prefer detecting the language from the path name rather than the
                   extension.

           -       dh_auto_install will now only create the destination directory it needs.  Previously, it
                   would create the package build directory for all packages.  This will not affect packages
                   that only build with debhelper commands, but it may expose bugs in commands not included in
                   debhelper.

           -       The helpers dh_installdocs, dh_installexamples, dh_installinfo, and dh_installman now error
                   out if their config has a pattern that does not match anything or reference a path that does
                   not exist.

                   Known exceptions include building with the nodoc profile, where the above tools will silently
                   permit failed matches where the patterns are used to specify documentation.

           -       The helpers dh_installdocs, dh_installexamples, dh_installinfo, and dh_installman now accept
                   the parameter --sourcedir with same meaning as dh_install. Furthermore, they now also fall
                   back to debian/tmp like dh_install.

                   Migration note: A bug in debhelper 11 up to 11.1.5 made dh_installinfo incorrectly ignore
                   --sourcedir.

           -       The perl-makemaker and perl-build build systems no longer pass -I. to perl.  Packages that
                   still need this behaviour can emulate it by using the PERL5LIB environment variable.  E.g. by
                   adding export PERL5LIB=. in their debian/rules file (or similar).

           -       The PERL_USE_UNSAFE_INC environment variable is no longer set by dh or any of the dh_auto_*
                   tools.  It was added as a temporary work around to avoid a lot of packages failing to build
                   at the same time.

                   Note this item will eventually become obsolete as upstream intends to drop support for the
                   PERL_USE_UNSAFE_INC environment variable.  When perl drops support for it, then this variable
                   will be removed retroactively from existing compat levels as well.

           -       The dh_makeshlibs helper will now exit with an error if objdump returns a non-zero exit from
                   analysing a given file.

           -       The dh_installdocs and dh_installexamples tools may now install most of the documentation in
                   a different path to comply with the recommendation from Debian policy §12.3 (since version
                   3.9.7).

                   Note that if a given source package only contains a single binary package in debian/control
                   or none of the packages are -doc packages, then this change is not relevant for that source
                   package and you can skip to the next change.

                   By default, these tools will now attempt to determine a "main package for the documentation"
                   (called a doc-main-package from here on) for every -doc package.  If they find such a doc-
                   main-package, they will now install the documentation into the path /usr/share/doc/doc-main-
                   package in the given doc package.  I.e. the path can change but the documentation is still
                   shipped in the -doc package.

                   The --doc-main-package option can be used when the auto-detection is insufficient or to reset
                   the path to its previous value if there is a reason to diverge from Debian policy
                   recommendation.

                   Some documentation will not be affected by this change.  These exceptions include the
                   copyright file, changelog files, README.Debian, etc.  These files will still be installed in
                   the path /usr/share/doc/package.

           -       The dh_strip and dh_shlibdeps tools no longer uses filename patterns to determine which files
                   to process.  Instead, they open the file and look for an ELF header to determine if a given
                   file is an shared object or an ELF executable.

                   This change may cause the tools to process more files than previously.

       v12 Changes from v11 are:

           -       The dh_makeshlibs tool now generates shlibs files with versioned dependency by default.  This
                   means that -VUpstream-Version (a.k.a. -V) is now the default.

                   If an unversioned dependency in the shlibs file is wanted, this can be obtained by passing
                   -VNone instead.  However, please see dh_makeshlibs(1) for the caveat of unversioned
                   dependencies.

           -       The -s (--same-arch) option is removed.  Please use -a (--arch) instead.

           -       Invoking dh_clean -k now causes an error instead of a deprecation warning.

           -       The --no-restart-on-upgrade option in dh_installinit has been removed.  Please use the new
                   name --no-stop-on-upgrade

           -       There was a bug in the doit (and similar) functions from Debian::Debhelper::Dh_Lib that made
                   them spawn a shell in one particular circumstance.  This bug is now removed and will cause
                   helpers that rely on the bug to fail with a "command not found"-error.

           -       The --list-missing and --fail-missing in dh_install has been removed.  Please use dh_missing
                   and its corresponding options, which can also see the files installed by other helpers.

           -       The dh_installinit helper no longer installs configuration for the upstart init system.
                   Instead, it will abort the build if it finds an old upstart configuration file.  The error is
                   there to remind the package maintainer to ensure the proper removal of the conffiles shipped
                   in previous versions of the package (if any).

           -       The dh_installdeb tool will do basic validation of some dpkg-maintscript-helper(1) commands
                   and will error out if the commands appear to be invalid.

           -       The dh_missing tool will now default to --list-missing.

           -       The dh_makeshlibs tool will now only pass libraries to dpkg-gensymbols(1) if the ELF binary
                   has a SONAME (containing ".so").

           -       The dh_compress tool no longer compresses examples (i.e. anything installed in
                   </usr/share/doc/package/examples>.)

           -       The standard sequence in dh now includes dh_dwz and dh_installinitramfs by default.  This
                   makes the dwz and installinitramfs sequences obsolete and they will now fail with an error.
                   If you want to skip these commands, then please insert an empty override target for them in
                   debian/rules (e.g. override_dh_dwz:)

           -       The build systems meson and autoconf no longer explicitly set the --libexecdir variable and
                   thus relies on the build system default - which should be /usr/libexec (per FHS 3.0, adopted
                   in Debian Policy 4.1.5).

                   If a particular upstream package does not use the correct default, the parameter can often be
                   passed manually via dh_auto_configure(1).  E.g.  via the following example:

                       override_dh_auto_configure:
                           dh_auto_configure -- --libexecdir=/usr/libexec

                   Note the -- before the --libexecdir parameter.

           -       Retroactively removed in debhelper/13.5:

                   The dh_installdeb tool would no longer installs the maintainer provided conffiles file as it
                   was deemed unnecessary.  However, the remove-on-upgrade from dpkg/1.20 made the file relevant
                   again and dh_installdeb now installs it again in compat levels 12+.

           -       The dh_installsystemd tool no longer relies on dh_installinit for handling systemd services
                   that have a sysvinit alternative.  Both tools must now be used in such a case to ensure the
                   service is properly started under both sysvinit and systemd.

                   If you have an override for dh_installinit (e.g. to call it with --no-start) then you will
                   probably need one for dh_installsystemd as well now.

                   This change makes dh_installinit inject a misc:Pre-Depends for init-system-helpers (>=
                   1.54~).  Please ensure that the package lists ${misc:Pre-Depends} in its Pre-Depends field
                   before upgrading to compat 12.

           -       The third-party dh_golang tool (from dh-golang package) now defaults on honoring
                   DH_GOLANG_EXCLUDES variable for source installation in -dev packages and not only during the
                   building process. Please set DH_GOLANG_EXCLUDES_ALL to false to revert to the previous
                   behaviour. See Debian::Debhelper::Buildsystem::golang(3pm) for details and examples.

           -       dh_installsystemduser is now included in the dh standard sequence by default.

           -       The python-distutils buildsystem is now removed.  Please use the third-party build system
                   pybuild instead.

       v13 This is the recommended mode of operation.

           Changes from v12 are:

           -       The meson+ninja build system now uses meson test instead of ninja test when running the test
                   suite.  Any override of dh_auto_test that passes extra parameters to upstream test runner
                   should be reviewed as meson test is not command line compatible with ninja test.

           -       All debhelper like tools based on the official debhelper library (including dh and the
                   official dh_* tools) no longer accepts abbreviated command parameters.  At the same time, dh
                   now optimizes out calls to redundant dh_* helpers even when passed long command line options.

           -       The ELF related debhelper tools (dh_dwz, dh_strip, dh_makeshlibs, dh_shlibdeps) are now only
                   run for arch dependent packages by default (i.e. they are excluded from *-indep targets and
                   are passed -a by default). If you need them for *-indep targets, you can add an explicit
                   Build-Depends on dh-sequence-elf-tools.

           -       The third-party gradle build system (from gradle-debian-helper package) now runs the
                   upstream-provided test suite automatically.  To suppress such behavior, override
                   dh_auto_test.

           -       The dh_installman tool now aborts if it sees conflicting definitions of a manpage.  This
                   typically happens if the upstream build system is installing a compressed version and the
                   package lists an uncompressed version of the manpage in debian/package.manpages.  Often the
                   easiest fix is to remove the manpage from debian/package.manpages (assuming both versions are
                   identical).

           -       The dh_auto_* helpers now reset the environment variables HOME and common XDG_* variable.
                   Please see description of the environment variables in "ENVIRONMENT" for how this is handled.

                   This feature changed between debhelper 13 and debhelper 13.2.

           -       The dh command will now error if an override or hook target for an obsolete command are
                   present in debian/rules (e.g. override_dh_systemd_enable:).

           -       The dh_missing command will now default to --fail-missing.  This can be reverted to a non-
                   fatal warning by explicitly passing --list-missing like it was in compat 12.

                   If you do not want the warning either, please omit the call to dh_missing.  If you use the dh
                   command sequencer, then you can do this by inserting an empty override target in the
                   debian/rules file of the relevant package.  As an example:

                       # Disable dh_missing
                       override_dh_missing:

           -       The dh command sequencer now runs dh_installtmpfiles in the default sequence.  The
                   dh_installtmpfiles takes over handling of tmpfiles.d configuration files.  Related
                   functionality in dh_installsystemd is now disabled.

                   Note that dh_installtmpfiles responds to debian/package.tmpfiles where dh_installsystemd used
                   a name without the trailing "s".

           -       Many dh_* tools now support limited variable expansion via the ${foo} syntax.  In many cases,
                   this can be used to reference paths that contain either spaces or dpkg-architecture(1)
                   values.  While this can reduce the need for dh-exec(1) in some cases, it is not a replacement
                   dh-exec(1) in general.  If you need filtering, renaming, etc., the package will still need
                   dh-exec(1).

                   Please see "Substitutions in debhelper config files" for syntax and available substitution
                   variables.  To dh_* tool writers, substitution expansion occurs as a part of the filearray
                   and filedoublearray functions.

           -       The dh command sequencer will now skip all hook and override targets for dh_auto_test, dh_dwz
                   and dh_strip when DEB_BUILD_OPTIONS lists the relevant nocheck / nostrip options.

                   Any package relying on these targets to always be run should instead move relevant logic out
                   of those targets.  E.g. non-test related packaging code from override_dh_auto_test would have
                   to be moved to execute_after_dh_auto_build or execute_before_dh_auto_install.

           -       The cmake buildsystem now passes -DCMAKE_SKIP_INSTALL_ALL_DEPENDENCY=ON to cmake(1) to speed
                   up automatic installation process. If for some reason you need previous behavior, override
                   the flag:

                       dh_auto_configure -- -DCMAKE_SKIP_INSTALL_ALL_DEPENDENCY=OFF ...

       v14 This compatibility level is still open for development; use with caution.

           Changes from v13 are:

           -       The cmake buildsystem now passes -DCMAKE_SKIP_RPATH=ON and -DCMAKE_BUILD_RPATH_USE_ORIGIN=ON
                   to cmake(1) to avoid some reproducibility issues.

                   This can cause issues with running binaries directly from the build directories as they might
                   now require a manually set LD_LIBRARY_PATH.  If you need to override this change, we
                   recommend that you try to pass the -DCMAKE_SKIP_RPATH=OFF option first to see if that fixes
                   the problem (leaving CMAKE_BUILD_RPATH_USE_ORIGIN at its new default).  This should undo the
                   need for LD_LIBRARY_PATH and avoid the reproducibility issues on Linux, where $ORIGIN is
                   supported by the runtime linkers.

           -       The tool dh_installsysusers is now included in the default sequence. It will cause units to
                   be automatically started on installation, restarted on upgrade and stopped on removal for
                   every systemd user instance running on the system.

           -       Use of the dh_gconf command in override and hook targets now causes an error.  The dh_gconf
                   command has been a no-op for years and was removed in debhelper 13.4.

           -       The dh sequencer will warn if the single-binary addon is implicitly activated to warn
                   maintainers of the pending compat 15 change in dh_auto_install.

                   Maintainers are urged to either explicitly activate the single-binary addon to preserve the
                   existing behaviour (e.g., by adding dh-sequence-single-binary to Build-Depends), or
                   explicitly passing --destdir to dh_auto_install if used and then passing --without single-
                   binary to dh (the latter to silence the warning).

                   The rationale for this change to avoid "surprises" when adding a second binary package later.
                   Previously, debhelper would silently change behaviour often resulting in empty binary
                   packages being uploaded to the archive by mistake. With the new behaviour, the single-binary
                   addon will detect the mismatch and warn the maintainer of what is about to happen.

       v15 This compatibility level is still open for development; use with caution.

           Changes from v14 are:

           -       The dh_auto_install tool no longer defaults to --destdir=debian/package for source packages
                   only producing a single binary.  If this behaviour is wanted, the package should explicitly
                   activate the single-binary dh addon (e.g., by adding dh-sequence-single-binary to Build-
                   Depends) or pass --destdir to dh_auto_install.

                   The rationale for this change to avoid "surprises" when adding a second binary package later.
                   Previously, debhelper would silently change behaviour often resulting in empty binary
                   packages being uploaded to the archive by mistake. With the new behaviour, the single-binary
                   addon will detect the mismatch and warn the maintainer of what is about to happen.

NOTES

   Multiple binary package support
       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, with the exceptions below.

       First, any package whose Architecture field in debian/control does not match the DEB_HOST_ARCH
       architecture will be excluded ("Debian Policy, section 5.6.8").

       Also, some additional packages may be excluded based on the contents of the DEB_BUILD_PROFILES
       environment variable and Build-Profiles fields in binary package stanzas in debian/control, according to
       the draft policy at <https://wiki.debian.org/BuildProfileSpec>.

       Interaction between package selections and Build-Profiles

       Build-Profiles affect which packages are included in the package selections mechanisms in debhelper.
       Generally, the package selections are described from the assumption that all packages are enabled.  This
       section describes how the selections react when a package is disabled due to the active Build-Profiles
       (or lack of active Build-Profiles).

       -a/--arch, -i/--indep OR no selection options (a raw "dh_X" call)
           The package disabled by Build-Profiles is silently excluded from the selection.

           Note you will receive a warning if all packages related to these selections are disabled.  In that
           case, it generally does not make sense to do the build in the first place.

       -N package / --no-package package
           The option is accepted and effectively does nothing.

       -p package / --package package
           The option is accepted, but debhelper will not act on the package.

       Note that it does not matter whether a package is enabled or disabled by default.

   Automatic generation of Debian install scripts
       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 $1, $2,
       etc are set with the set command):

         my $temp="set -e\nset -- @ARGV\n" . << 'EOF';
         #DEBHELPER#
         EOF
         if (system($temp)) {
            my $exit_code = ($? >> 8) & 0xff;
            my $signal = $? & 0x7f;
            if ($exit_code) {
                die("The debhelper script failed with error code: ${exit_code}");
            } else {
                die("The debhelper script was killed by signal: ${signal}");
            }
         }

   Automatic generation of miscellaneous dependencies.
       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 dependent 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.

   Package build directories
       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.

   udebs
       Debhelper includes support for udebs. To create a udeb with debhelper, add "Package-Type: udeb" to the
       package's stanza in debian/control.  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.

ENVIRONMENT

       This section describes some of the environment variables that influences the behaviour of debhelper or
       which debhelper interacts with.

       It is important to note that these must be actual environment variables in order to affect the behaviour
       of debhelper (not simply Makefile variables).  To specify them properly in debian/rules, be sure to
       "export" them. For example, "export DH_VERBOSE".

       DH_VERBOSE
           Set to 1 to enable verbose mode. Debhelper will output every command it runs. Also enables verbose
           build logs for some build systems like autoconf.

       DH_QUIET
           Set to 1 to enable quiet mode. Debhelper will not output commands calling the upstream build system
           nor will dh print which subcommands are called and depending on the upstream build system might make
           that more quiet, too.  This makes it easier to spot important messages but makes the output quite
           useless as buildd log.  Ignored if DH_VERBOSE is also set.

       DH_COMPAT
           Temporarily specifies what compatibility level debhelper should run at, overriding any value
           specified via Build-Depends on debhelper-compat or via the debian/compat file.

       DH_NO_ACT
           Set to 1 to enable no-act mode.

       DH_OPTIONS
           All debhelper tools will parse command line arguments listed in this variable before any command
           option (as if they had been prepended to the command line arguments).  Unfortunately, some third-
           party provided tools may not support this variable and will ignore these command line arguments.

           When using dh(1), it can be passed options that will be passed on to each debhelper command, which is
           generally better than using DH_OPTIONS.

       DH_ALWAYS_EXCLUDE
           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 CVS source tree, in which case setting
           DH_ALWAYS_EXCLUDE=CVS will prevent any CVS directories from sneaking into the package you build. Or,
           if a package has a source tarball that (unwisely) includes CVS 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

       DH_EXTRA_ADDONS
           If set, this adds the specified dh addons to be run in the appropriate places in the sequence of
           commands. This is equivalent to specifying the addon to run with the --with flag in the debian/rules
           file. Any --without calls specifying an addon in this environment variable will not be run.

           This is intended to be used by downstreams or specific local configurations that require a debhelper
           addon to be run during multiple builds without having to patch a large number of rules file. If at
           all possible, this should be avoided in favor of a --with flag in the rules file.

       DH_COLORS, DPKG_COLORS
           These variables can be used to control whether debhelper commands should use colors in their textual
           output.  Can be set to "always", "auto" (the default), or "never".

           Note that DPKG_COLOR also affects a number of dpkg related tools and debhelper uses it on the
           assumption that you want the same color setting for dpkg and debhelper.  In the off-hand chance you
           want different color setting for debhelper, you can use DH_COLORS instead or in addition to
           DPKG_COLORS.

       NO_COLOR
           If no explicit request for color has been given (e.g. DH_COLORS and DPKG_COLORS are both unset), the
           presence of this environment variable cause the default color setting to be "never".

           The variable is defined according to <https://no-color.org/>.  In this project, the environment
           variables (such as DH_COLORS) are considered an explicit request for color.

       CFLAGS, CPPFLAGS, CXXFLAGS, OBJCFLAGS, OBJCXXFLAGS, GCJFLAGS, FFLAGS, FCFLAGS, LDFLAGS
           By default (in any non-deprecated compat level), debhelper will automatically set these flags by
           using dpkg-buildflags(1), when they are unset.  If you need to change the default flags, please use
           the features from dpkg-buildflags(1) to do this (e.g. DEB_BUILD_MAINT_OPTIONS=hardening=all or
           DEB_CPPFLAGS_MAINT_APPEND=-DCUSTOM_MACRO=true) rather than setting the concrete variable directly.

       HOME, XDG_*
           In compat 13 and later, these environment variables are reset before invoking the upstream build
           system via the dh_auto_* helpers.  The variables HOME (all dh_auto_* helpers) and XDG_RUNTIME_DIR
           (dh_auto_test only) will be set to a writable directory. All remaining variables and XDG_RUNTIME_DIR
           (except for during dh_auto_test) will be cleared.

           The HOME directory will be created as an empty directory but it will be reused between calls to
           dh_auto_*.  Any content will persist until explicitly deleted or dh_clean.

       DEB_BUILD_OPTIONS
           Please see "Supported flags in DEB_BUILD_OPTIONS" for this environment variable.

           Please note that this variable should not be altered by package maintainers inside debian/rules to
           change the behaviour of debhelper.  Instead, where the package maintainer need these features, they
           should look disabling the relevant feature directly (e.g. by overriding the concrete tools).

       DEB_MAINT_BUILD_OPTIONS
           This is a dpkg specific environment variable (see e.g. dpkg-buildflags(1)).  The debhelper tool suite
           silently ignores it.

           It is documented here because it has a similar name to DEB_BUILD_OPTIONS, which make some people
           mistakenly assume that debhelper will also react to this variable.

   Supported flags in DEB_BUILD_OPTIONS
       The debhelper tool suite reacts to the following flags in DEB_BUILD_OPTIONS.

       dherroron=obsolete-compat-levels
           This is a debhelper specific value.

           When dherroron is present and set to obsolete-compat-levels, then debhelper tools will promote
           deprecation warnings for usage of old soon to be removed compat levels into errors.

           This is useful for automated checking for code relying on deprecated compat levels that is scheduled
           for removal.

           This option is intended for testing purposes; not production builds.

       nostrip
           This value will change the content of the debs being built.  The .deb packages built when this is set
           is therefore not bit-for-bit reproducible with a regular build in the general case.

           This value will cause the official debhelper tools will skip actions and helpers that either remove,
           detach or deduplicate debugging symbols in ELF binaries.

           This value affects dh_dwz(1) and dh_strip(1).

       nocheck
           This value will cause the official debhelper build systems to skip runs of upstream test suites.

           Package maintainers looking to avoid running the upstream tests should not rely on this.  Instead,
           they can add an empty override target to skip dh_auto_test.

           This value affects dh_auto_test(1).

       nodoc
           This value will change the content of the debs being built.  The .deb packages built when this is set
           is therefore not bit-for-bit reproducible with a regular build in the general case.

           This value will cause several debhelper tools to skip installation of documentation such as manpages
           or upstream provided documentation.  Additionally, the tools will also ignore if declared
           documentation is "missing" on the assumption that the documentation has not been built.

           This value effects tools like dh_installdocs(1), which knows it is working with documentation.

       noautodbgsym, noddebs
           The official name is autodbgsym.  The noddebs variant is accepted for historical reasons.

           This value causes debhelper to skip the generation of automatically generated debug symbol packages.

           This value affects dh_strip(1).

       parallel=N
           This value enables debhelper to use up to N threads or processes (subject to parameters like
           --no-parallel and --max-parallel=M).  Not all debhelper tools work with parallel tasks and may
           silently ignore the request.

           This value affects many debhelper tools.  Most notably dh_auto_*, which will attempt to run the
           underlying upstream build system with that number of threads.

       terse
           This value will cause the official debhelper build systems to configure upstream builds to be terse
           (i.e. reduce verbosity in their output).  This is subject to the upstream and the debhelper build
           system supporting such features.

           This value affects most dh_auto_* tools.

       Unknown flags are silently ignored.

       Note third-party debhelper-like tools or third-party provided build systems may or may not react to the
       above flags.  This tends to depend on implementation details of the tool.

SEE ALSO

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

       <http://joeyh.name/code/debhelper/>
           Debhelper web site.

AUTHOR

       Joey Hess <joeyh@debian.org>