Table of Contents
There is an old Latin saying: “Longum iter est per praecepta, breve et efficax per exempla” (“It’s a long way by the rules, but short and efficient with examples”).
Here is an example of creating a simple Debian package from a simple C source using the Makefile as its build system.
Let’s assume this upstream tarball to be debhello-0.0.tar.gz.
This type of source is meant to be installed as a non-system file as:
$ tar -xzmf debhello-0.0.tar.gz $ cd debhello-0.0 $ make $ make install
Debian packaging requires changing this “make install” process to install files to the target system image location instead of the normal location under /usr/local.
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Examples of creating a Debian package from other complicated build systems are described in Chapter 8, More Examples. |
The big picture for building a single non-native Debian package from the upstream tarball debhello-0.0.tar.gz can be summarized as:
The debmake command debianizes the upstream source tree by adding template files only in the debian directory.
The debuild command builds the binary package from the debianized source tree.
Big picture of package building.
$ tar -xzmf debhello-0.0.tar.gz $ cd debhello-0.0 $ debmake ... manual customization $ debuild ...
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The debuild command in this and following examples may be substituted by equivalent commands such as the sbuild command. |
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If the upstream tarball in the .tar.xz format is available, use it instead of the one in the .tar.gz and .tar.bz2 formats. The xz compression format offers the better compression than the gzip and bzip2 compressions. |
The debmake command is the helper script for the Debian packaging.
These features make Debian packaging with debmake simple and modern.
In retrospective, I created debmake to simplify this documentation. I consider debmake to be more-or-less a demonstration session generator for tutorial purpose.
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Many packages are packaged using only a text editor while imitating how other similar packages are packaged and consulting how the Debian policy requires us to do. This seems to me the most popular method for the real-life packaging activity. |
The debmake command isn’t the only helper script to make a Debian package. If you are interested alternative packaging helper tools, please see:
Here is a summary of commands similar to the debuild command.
The dpkg-buildpackage command is the official command to build the Debian binary package. For normal binary build, it executes roughly:
“debsign” (sign the *.dsc and *.changes files)
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See dpkg-buildpackage(1) for exact details. |
Let’s get the upstream source.
Download debhello-0.0.tar.gz.
$ wget http://www.example.org/download/debhello-0.0.tar.gz ... $ tar -xzf debhello-0.0.tar.gz $ tree . ├── debhello-0.0 │ ├── LICENSE │ ├── Makefile │ └── src │ └── hello.c └── debhello-0.0.tar.gz 2 directories, 4 files
Here, the C source hello.c is a very simple one.
hello.c.
$ cat debhello-0.0/src/hello.c #include <stdio.h> int main() { printf("Hello, world!\n"); return 0; }
Here, the Makefile supports GNU Coding Standards and FHS. Notably:
Makefile.
$ cat debhello-0.0/Makefile prefix = /usr/local all: src/hello src/hello: src/hello.c @echo "CFLAGS=$(CFLAGS)" | \ fold -s -w 70 | \ sed -e 's/^/# /' $(CC) $(CPPFLAGS) $(CFLAGS) $(LDCFLAGS) -o $@ $^ install: src/hello install -D src/hello \ $(DESTDIR)$(prefix)/bin/hello clean: -rm -f src/hello distclean: clean uninstall: -rm -f $(DESTDIR)$(prefix)/bin/hello .PHONY: all install clean distclean uninstall
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The echo of the $(CFLAGS) variable is used to verify the proper setting of the build flag in the following example. |
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If the debmake command is invoked with the -T option, more verbose comments are generated for the template files. |
The output from the debmake command is very verbose and explains what it does as follows.
$ cd debhello-0.0 $ debmake I: set parameters I: ================================================================= I: package_dir = /usr/lib/python3/dist-packages I: base_path = /usr I: base_lib_path = /usr/lib/debmake I: base_share_path = /usr/share/debmake I: ================================================================= I: sanity check of parameters I: pkg="debhello", ver="0.0", rev="1" I: *** start packaging in "debhello-0.0". *** I: provide debhello_0.0.orig.tar.gz for non-native Debian package I: pwd = "/path/to" I: $ ln -sf debhello-0.0.tar.gz debhello_0.0.orig.tar.gz I: pwd = "/path/to/debhello-0.0" I: parse binary package settings: I: binary package=debhello Type=bin / Arch=any M-A=foreign I: analyze the source tree I: build_type = make I: scan source for copyright+license text and file extensions I: 100 %, ext = c I: check_all_licenses I: .. I: check_all_licenses completed for 2 files. I: bunch_all_licenses I: format_all_licenses I: make debian/* template files I: single binary package I: debmake -x "1" ... I: creating => debian/control I: creating => debian/copyright I: substituting => /usr/share/debmake/extra0/changelog I: creating => debian/changelog I: substituting => /usr/share/debmake/extra0/rules I: creating => debian/rules I: substituting => /usr/share/debmake/extra1/README.Debian I: creating => debian/README.Debian I: substituting => /usr/share/debmake/extra1/watch I: creating => debian/watch I: substituting => /usr/share/debmake/extra1source/format I: creating => debian/source/format I: substituting => /usr/share/debmake/extra1tests/control I: creating => debian/source/control I: substituting => /usr/share/debmake/extra1upstream/metadata I: creating => debian/upstream/metadata I: substituting => /usr/share/debmake/extra1tests/control I: creating => debian/tests/control I: substituting => /usr/share/debmake/extra1patches/series I: creating => debian/patches/series I: substituting => /usr/share/debmake/extra1sourcex/local-options I: creating => debian/source/local-options I: substituting => /usr/share/debmake/extra1sourcex/options I: creating => debian/source/options I: substituting => /usr/share/debmake/extra1sourcex/patch-header I: creating => debian/source/patch-header I: run "debmake -x2" to get more template files I: $ wrap-and-sort
The debmake command generates all these template files based on command line options. Since no options are specified, the debmake command chooses reasonable default values for you:
Let’s inspect generated template files.
The source tree after the basic debmake execution.
$ cd .. $ tree . ├── debhello-0.0 │ ├── LICENSE │ ├── Makefile │ ├── debian │ │ ├── README.Debian │ │ ├── changelog │ │ ├── control │ │ ├── copyright │ │ ├── patches │ │ │ └── series │ │ ├── rules │ │ ├── source │ │ │ ├── control │ │ │ ├── format │ │ │ ├── local-options │ │ │ ├── options │ │ │ └── patch-header │ │ ├── tests │ │ │ └── control │ │ ├── upstream │ │ │ └── metadata │ │ └── watch │ └── src │ └── hello.c ├── debhello-0.0.tar.gz └── debhello_0.0.orig.tar.gz -> debhello-0.0.tar.gz 7 directories, 19 files
The debian/rules file is the build script provided by the package maintainer. Here is its template file generated by the debmake command.
debian/rules (template file):
$ cat debhello-0.0/debian/rules #!/usr/bin/make -f # You must remove unused comment lines for the released package. #export DH_VERBOSE = 1 #export DEB_BUILD_MAINT_OPTIONS = hardening=+all #export DEB_CFLAGS_MAINT_APPEND = -Wall -pedantic #export DEB_LDFLAGS_MAINT_APPEND = -Wl,--as-needed %: dh $@ #override_dh_auto_install: # dh_auto_install -- prefix=/usr #override_dh_install: # dh_install --list-missing -X.pyc -X.pyo
This is essentially the standard debian/rules file with the dh command. (There are some commented out contents for you to customize it.)
The debian/control file provides the main meta data for the Debian package. Here is its template file generated by the debmake command.
debian/control (template file):
$ cat debhello-0.0/debian/control Source: debhello Section: unknown Priority: optional Maintainer: "Firstname Lastname" <[email protected]> Build-Depends: debhelper-compat (= 13) Standards-Version: 4.5.1 Homepage: <insert the upstream URL, if relevant> Rules-Requires-Root: no Package: debhello Architecture: any Multi-Arch: foreign Depends: ${misc:Depends}, ${shlibs:Depends} Description: auto-generated package by debmake This Debian binary package was auto-generated by the debmake(1) command provided by the debmake package.
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If you leave “Section: unknown” in the template debian/control file unchanged, the lintian error may cause the build to fail. |
Since this is the ELF binary executable package, the debmake command sets “Architecture: any” and “Multi-Arch: foreign”. Also, it sets required substvar parameters as “Depends: ${shlibs:Depends}, ${misc:Depends}”. These are explained in Chapter 5, Basics.
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Please note this debian/control file uses the RFC-822 style as documented in 5.2 Source package control files — debian/control of the “Debian Policy Manual”. The use of the empty line and the leading space are significant. |
The debian/copyright file provides the copyright summary data of the Debian package. Here is its template file generated by the debmake command.
debian/copyright (template file):
$ cat debhello-0.0/debian/copyright Format: https://www.buy-develop.eu.org/doc/packaging-manuals/copyright-format/1.0/ Upstream-Name: debhello Upstream-Contact: <preferred name and address to reach the upstream project> Source: <url://example.com> # # Please double check copyright with the licensecheck(1) command. Files: Makefile src/hello.c Copyright: __NO_COPYRIGHT_NOR_LICENSE__ License: __NO_COPYRIGHT_NOR_LICENSE__ #----------------------------------------------------------------------------... # Files marked as NO_LICENSE_TEXT_FOUND may be covered by the following # license/copyright files. #----------------------------------------------------------------------------... # License file: LICENSE License: . All files in this archive are licensed under the MIT License as below. . Copyright 2015 Osamu Aoki <[email protected]> . Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: . The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. . THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Some manual modification is required to make the proper Debian package as a maintainer.
In order to install files as a part of the system files, the $(prefix) value of /usr/local in the Makefile should be overridden to be /usr. This can be accommodated by the following the debian/rules file with the override_dh_auto_install target setting “prefix=/usr”.
debian/rules (maintainer version):
$ vim debhello-0.0/debian/rules ... hack, hack, hack, ... $ cat debhello-0.0/debian/rules #!/usr/bin/make -f export DH_VERBOSE = 1 export DEB_BUILD_MAINT_OPTIONS = hardening=+all export DEB_CFLAGS_MAINT_APPEND = -Wall -pedantic export DEB_LDFLAGS_MAINT_APPEND = -Wl,--as-needed %: dh $@ override_dh_auto_install: dh_auto_install -- prefix=/usr
Exporting the DH_VERBOSE environment variable in the debian/rules file as above forces the debhelper tool to make a fine grained build report.
Exporting DEB_BUILD_MAINT_OPTION as above sets the hardening options as described in the “FEATURE AREAS/ENVIRONMENT” in dpkg-buildflags(1). [9]
Exporting DEB_CFLAGS_MAINT_APPEND as above forces the C compiler to emit all the warnings.
Exporting DEB_LDFLAGS_MAINT_APPEND as above forces the linker to link only when the library is actually needed. [10]
The dh_auto_install command for the Makefile based build system essentially runs “$(MAKE) install DESTDIR=debian/debhello”. The creation of this override_dh_auto_install target changes its behavior to “$(MAKE) install DESTDIR=debian/debhello prefix=/usr”.
Here are the maintainer versions of the debian/control and debian/copyright files.
debian/control (maintainer version):
$ vim debhello-0.0/debian/control ... hack, hack, hack, ... $ cat debhello-0.0/debian/control Source: debhello Section: devel Priority: optional Maintainer: Osamu Aoki <[email protected]> Build-Depends: debhelper-compat (= 13) Standards-Version: 4.5.1 Homepage: https://salsa.debian.org/debian/debmake-doc Rules-Requires-Root: no Package: debhello Architecture: any Multi-Arch: foreign Depends: ${misc:Depends}, ${shlibs:Depends} Description: Simple packaging example for debmake This Debian binary package is an example package. (This is an example only)
debian/copyright (maintainer version):
$ vim debhello-0.0/debian/copyright ... hack, hack, hack, ... $ cat debhello-0.0/debian/copyright Format: https://www.buy-develop.eu.org/doc/packaging-manuals/copyright-format/1.0/ Upstream-Name: debhello Upstream-Contact: Osamu Aoki <[email protected]> Source: https://salsa.debian.org/debian/debmake-doc Files: * Copyright: 2015-2021 Osamu Aoki <[email protected]> License: Expat Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: . The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. . THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
There are several other template files under the debian/ directory. These also need to be updated.
Template files under debian/. (v=0.0):
$ tree debhello-0.0/debian debhello-0.0/debian ├── README.Debian ├── changelog ├── control ├── copyright ├── patches │ └── series ├── rules ├── source │ ├── control │ ├── format │ ├── local-options │ ├── options │ └── patch-header ├── tests │ └── control ├── upstream │ └── metadata └── watch 4 directories, 14 files
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Configuration files used by the dh_* commands from the debhelper package usually treat # as the start of a comment line. |
You can create a non-native Debian package using the debuild command or its equivalents (see Section 4.4, “What is debuild?”) in this source tree. The command output is very verbose and explains what it does as follows.
$ cd debhello-0.0 $ debuild dpkg-buildpackage -us -uc -ui -i -i ... debian/rules clean dh clean ... debian/rules binary dh binary dh_update_autotools_config dh_autoreconf dh_auto_configure install -d /path/to/debhello-0.0/debian/.debhelper/generated/_source/... dh_auto_build make -j12 "INSTALL=install --strip-program=true" make[1]: Entering directory '/path/to/debhello-0.0' # CFLAGS=-g -O2 # -ffile-prefix-map=/home/osamu/src/public/debmake-doc/debmake-doc/examp ... Now running lintian -i -I --show-overrides debhello_0.0-1_amd64.changes ... ... N: Renamed from: binary-without-manpage N: W: debhello: readme-debian-contains-debmake-template N: ...
You can verify that CFLAGS is updated properly with -Wall and -pedantic by the DEB_CFLAGS_MAINT_APPEND variable.
The manpage should be added to the package as reported by the lintian package, as shown in later examples (see Chapter 8, More Examples). Let’s move on for now.
Let’s inspect the result.
The generated files of debhello version 0.0 by the debuild command:
$ cd .. $ tree -FL 1 . ├── debhello-0.0/ ├── debhello-0.0.tar.gz ├── debhello-dbgsym_0.0-1_amd64.deb ├── debhello_0.0-1.debian.tar.xz ├── debhello_0.0-1.dsc ├── debhello_0.0-1_amd64.build ├── debhello_0.0-1_amd64.buildinfo ├── debhello_0.0-1_amd64.changes ├── debhello_0.0-1_amd64.deb └── debhello_0.0.orig.tar.gz -> debhello-0.0.tar.gz 1 directory, 9 files
You see all the generated files.
The debhello_0.0-1.debian.tar.xz contains the Debian changes to the upstream source as follows.
The compressed archive contents of debhello_0.0-1.debian.tar.xz:
$ tar -tzf debhello-0.0.tar.gz debhello-0.0/ debhello-0.0/src/ debhello-0.0/src/hello.c debhello-0.0/LICENSE debhello-0.0/Makefile $ tar --xz -tf debhello_0.0-1.debian.tar.xz debian/ debian/README.Debian debian/changelog debian/control debian/copyright debian/patches/ debian/patches/series debian/rules debian/source/ debian/source/control debian/source/format debian/source/options debian/source/patch-header debian/tests/ debian/tests/control debian/upstream/ debian/upstream/metadata debian/watch
The debhello_0.0-1_amd64.deb contains the binary files to be installed to the target system.
The debhello-debsym_0.0-1_amd64.deb contains the debug symbol files to be installed to the target system..
The binary package contents of all binary packages:
$ dpkg -c debhello-dbgsym_0.0-1_amd64.deb drwxr-xr-x root/root ... ./ drwxr-xr-x root/root ... ./usr/ drwxr-xr-x root/root ... ./usr/lib/ drwxr-xr-x root/root ... ./usr/lib/debug/ drwxr-xr-x root/root ... ./usr/lib/debug/.build-id/ drwxr-xr-x root/root ... ./usr/lib/debug/.build-id/be/ -rw-r--r-- root/root ... ./usr/lib/debug/.build-id/be/11292eded3fc22396a0b62... drwxr-xr-x root/root ... ./usr/share/ drwxr-xr-x root/root ... ./usr/share/doc/ lrwxrwxrwx root/root ... ./usr/share/doc/debhello-dbgsym -> debhello $ dpkg -c debhello_0.0-1_amd64.deb drwxr-xr-x root/root ... ./ drwxr-xr-x root/root ... ./usr/ drwxr-xr-x root/root ... ./usr/bin/ -rwxr-xr-x root/root ... ./usr/bin/hello drwxr-xr-x root/root ... ./usr/share/ drwxr-xr-x root/root ... ./usr/share/doc/ drwxr-xr-x root/root ... ./usr/share/doc/debhello/ -rw-r--r-- root/root ... ./usr/share/doc/debhello/README.Debian -rw-r--r-- root/root ... ./usr/share/doc/debhello/changelog.Debian.gz -rw-r--r-- root/root ... ./usr/share/doc/debhello/copyright
The generated dependency list of all binary packages.
The generated dependency list of all binary packages (v=0.0):
$ dpkg -f debhello-dbgsym_0.0-1_amd64.deb pre-depends \ depends recommends conflicts breaks Depends: debhello (= 0.0-1) $ dpkg -f debhello_0.0-1_amd64.deb pre-depends \ depends recommends conflicts breaks Depends: libc6 (>= 2.2.5)
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Many more details need to be addressed before uploading the package to the Debian archive. |
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If manual adjustments of auto-generated configuration files by the debmake command are skipped, the generated binary package may lack meaningful package description and some of the policy requirements may be missed. This sloppy package functions well under the dpkg command, and may be good enough for your local deployment. |
The above example did not touch the upstream source to make the proper Debian package.
An alternative approach as the maintainer is to change the upstream source by modifying the upstream Makefile to set the $(prefix) value to /usr.
The packaging is practically the same as the above step-by-step example except for two points in Section 4.7, “Step 3: Modification to the template files”:
Store the maintainer modifications to the upstream source as the corresponding patch files in the debian/patches/ directory and list their filenames in the debian/patches/series file as indicated in Section 5.10, “debian/patches/*”. There are several ways to generate patch files. A few examples are given in these sections:
The maintainer modification to the debian/rules file doesn’t have the override_dh_auto_install target as follows:
debian/rules (alternative maintainer version):
$ cd debhello-0.0 $ vim debian/rules ... hack, hack, hack, ... $ cat debian/rules #!/usr/bin/make -f export DH_VERBOSE = 1 export DEB_BUILD_MAINT_OPTIONS = hardening=+all export DEB_CFLAGS_MAINT_APPEND = -Wall -pedantic export DEB_LDFLAGS_MAINT_APPEND = -Wl,--as-needed %: dh $@
This alternative approach to Debian packaging using a series of patch files may be less robust for future upstream changes but more flexible coping with the difficult upstream source. (See Section 7.13, “3.0 source format”.)
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For this particular packaging case, the above Section 4.7, “Step 3: Modification to the template files” using the debian/rules file is the better approach. But let’s keep on with this approach as a leaning process. |
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For more complicated packaging cases, both Section 4.7, “Step 3: Modification to the template files” and Section 4.9, “Step 3 (alternative): Modification to the upstream source” approaches need to be deployed. |
Here is an example to create 000-prefix-usr.patch by the diff command.
$ cp -a debhello-0.0 debhello-0.0.orig $ vim debhello-0.0/Makefile ... hack, hack, hack, ... $ diff -Nru debhello-0.0.orig debhello-0.0 >000-prefix-usr.patch $ cat 000-prefix-usr.patch diff -Nru debhello-0.0.orig/Makefile debhello-0.0/Makefile --- debhello-0.0.orig/Makefile 2021-07-02 16:26:38.734722687 +0900 +++ debhello-0.0/Makefile 2021-07-02 16:26:38.802723496 +0900 @@ -1,4 +1,4 @@ -prefix = /usr/local +prefix = /usr all: src/hello $ rm -rf debhello-0.0 $ mv -f debhello-0.0.orig debhello-0.0
Please note that the upstream source tree is restored to the original state and the patch file is available as 000-prefix-usr.patch.
This 000-prefix-usr.patch is edited to be DEP-3 conformant and moved to the right location as below.
$ cd debhello-0.0 $ echo '000-prefix-usr.patch' >debian/patches/series $ vim ../000-prefix-usr.patch ... hack, hack, hack, ... $ mv -f ../000-prefix-usr.patch debian/patches/000-prefix-usr.patch $ cat debian/patches/000-prefix-usr.patch From: Osamu Aoki <[email protected]> Description: set prefix=/usr patch diff -Nru debhello-0.0.orig/Makefile debhello-0.0/Makefile --- debhello-0.0.orig/Makefile +++ debhello-0.0/Makefile @@ -1,4 +1,4 @@ -prefix = /usr/local +prefix = /usr all: src/hello
Here is an example to create 000-prefix-usr.patch by the dquilt command which is a simple wrapper of the quilt program. The syntax and function of the dquilt command is the same as the quilt(1) command, except for the fact that the patch is stored in the debian/patches/ directory.
$ cd debhello-0.0 $ dquilt new 000-prefix-usr.patch Patch debian/patches/000-prefix-usr.patch is now on top $ dquilt add Makefile File Makefile added to patch debian/patches/000-prefix-usr.patch ... hack, hack, hack, ... $ head -1 Makefile prefix = /usr $ dquilt refresh Refreshed patch debian/patches/000-prefix-usr.patch $ dquilt header -e --dep3 ... edit the DEP-3 patch header with editor $ tree -a . ├── .pc │ ├── .quilt_patches │ ├── .quilt_series │ ├── .version │ ├── 000-prefix-usr.patch │ │ ├── .timestamp │ │ └── Makefile │ └── applied-patches ├── LICENSE ├── Makefile ├── debian │ ├── README.Debian │ ├── changelog │ ├── control │ ├── copyright │ ├── patches │ │ ├── 000-prefix-usr.patch │ │ └── series │ ├── rules │ ├── source │ │ ├── control │ │ ├── format │ │ ├── local-options │ │ ├── options │ │ └── patch-header │ ├── tests │ │ └── control │ ├── upstream │ │ └── metadata │ └── watch └── src └── hello.c 8 directories, 24 files $ cat debian/patches/series 000-prefix-usr.patch $ cat debian/patches/000-prefix-usr.patch Description: set prefix=/usr patch Author: Osamu Aoki <[email protected]> Index: debhello-0.0/Makefile =================================================================== --- debhello-0.0.orig/Makefile +++ debhello-0.0/Makefile @@ -1,4 +1,4 @@ -prefix = /usr/local +prefix = /usr all: src/hello
Here, Makefile in the upstream source tree doesn’t need to be restored to the original state. The dpkg-source command invoked by the Debian packaging procedure in Section 4.8, “Step 4: Building package with debuild”, understands the patch application state recorded by the dquilt program in the .pc/ directory. As long as all the changes are committed by the dquilt command, the Debian source package can be built from the modified source tree.
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If the .pc/ directory is missing, the dpkg-source command assumes that no patch was applied. That’s why the more primitive patch generation methods like in Section 4.9.1, “Patch by diff -u” without generating the .pc/ directory require the upstream source tree to be restored. |
Here is an example to create 000-prefix-usr.patch by the “dpkg-source --commit” command.
Let’s edit the upstream source.
$ cd debhello-0.0 $ vim Makefile ... hack, hack, hack, ... $ head -n1 Makefile prefix = /usr
Let’s commit it.
$ dpkg-source --commit . 000-prefix-usr.patch ... editor to edit the DEP-3 patch header ...
Let’s see the result.
$ cat debian/patches/series 000-prefix-usr.patch $ cat debian/patches/000-prefix-usr.patch Description: set prefix=/usr patch Author: Osamu Aoki <[email protected]> Index: debhello-0.0/Makefile --- debhello-0.0.orig/Makefile +++ debhello-0.0/Makefile @@ -1,4 +1,4 @@ -prefix = /usr/local +prefix = /usr all: src/hello $ tree -a . ├── .pc │ ├── .quilt_patches │ ├── .quilt_series │ ├── .version │ ├── 000-prefix-usr.patch │ │ ├── .timestamp │ │ └── Makefile │ └── applied-patches ├── LICENSE ├── Makefile ├── debian │ ├── README.Debian │ ├── changelog │ ├── control │ ├── copyright │ ├── patches │ │ ├── 000-prefix-usr.patch │ │ └── series │ ├── rules │ ├── source │ │ ├── control │ │ ├── format │ │ ├── local-options │ │ ├── options │ │ └── patch-header │ ├── tests │ │ └── control │ ├── upstream │ │ └── metadata │ └── watch └── src └── hello.c 8 directories, 24 files
Here, the dpkg-source command performs exactly the same as what the sequences of the dquilt command did in Section 4.9.2, “Patch by dquilt”.
[9] This is a cliché to force a read-only relocation link for the hardening and to prevent the lintian warning “W: debhello: hardening-no-relro usr/bin/hello”. This is not really needed for this example but should be harmless. The lintian tool seems to produce a false positive warning for this case which has no linked library.
[10] This is a cliché to prevent overlinking for the complex library dependency case such as Gnome programs. This is not really needed for this simple example but should be harmless.