Package Building

Fake package to satisfy dependencies

Newsgroups:  gmane.linux.debian.user
Date:        Sat, 2 Sep 2006 00:37:30 -0400

> I remember there is a tool that allows me to build a fake package which
> contains nothing but package info to satisfy dependencies from other
> packages. What it is?
>
> For example, I never use package Y, but (stupid) package X insists on
> the dependencies of Y. I want to build a fake Y just to make X happy.

You want the equivs package.

Roberto C. Sanchez

dpkg:equivs

Basic Info

Info

equivs - Circumvent Debian package dependencies

Tag: admin::package-management, devel::packaging, interface::commandline, made-of::lang:perl, role::sw:utility, suite::debian, works-with::software:package

Description

This package provides a tool to create Debian packages that only contain dependency information.

One use for this is to create a metapackage: a package whose sole purpose is to declare dependencies and conflicts on other packages so that these will be automatically installed, upgraded, or removed.

Another use is to circumvent dependency checking. If a package P is not installed on the system, packages that depend on P cannot normally be installed. However, if functionality equivalent to P is known to be installed, this tool can be used to trick the Debian package management system into believing that package P is actually installed.

this should be considered a crude hack to work around awkward situations, not a normal solution. If you use equivs to work around bugs in other Debian packages, you should also file bug reports against those packages.

Help

Quick Help

To use equivs, you do:

cd /tmp

b.1. equivs-control ns-control or b.2. cp /usr/share/doc/equivs/examples/<a control file> ns-control

edit ns-control
equivs-build ns-control
su -
dpkg -i /tmp/ns-dummy_1.0_all.deb

Detail Help

When you call the "equivs-build" program, it will create a subdirectory "equivs", containing the files necessary to create a Debian package and build that package.

You need a control file for make-equivs. You will find examples of control files in /usr/share/doc/equivs/examples.

The control file has a structure like the control files in "real" Debian packages, but it doesn't have to define all keys, as default values will be used if you omit one. See the manual page for "equivs-build" for more information.

Building a custom version of wget

Newsgroups:  gmane.linux.debian.user
Date:        Sun, 15 May 2005 10:17:40 -0400

> Using the apt tools, I'd like to rebuild "wget" to enable the
> downloading files greater that 2GBytes in size. I understand that it's
> required that I pass "-D_FILE_OFFSET_BITS=64 " as an option to the
> compiler.

Personally, I would 'apt-get source wget', change into the resulting directory, and modify the call to configure inside of debian/rules.

I would also add a new entry to debian/changelog with a /different/ version number, so that you don't collide with whatever is in the official repository. For example, the current version of wget is 1.9.1-11 (in Sarge). I would add a changelog entry (you can do this by copying one already in there, or using debchange —version <num>) with the version number 1.9.1-11.0sanchez1. This will make sure that future revisions from Debian have the opportunity to upgrade yours (you prevent that frmo happening by placing the package on hold in your package management program). This also lets you make additional changes to the same version by incrementing the very last number.

Roberto C. Sanchez

Basics of the Debian package management system

http://www.debian.org/doc/FAQ/ch-pkg_basics.en.html

6.13 How do I install a source package?

Debian source packages can't actually be "installed", they are just unpacked in whatever directory you want to build the binary packages they produce.

Source packages are distributed on most of the same mirrors where you can obtain the binary packages. If you set up your APT's sources.list(5) to include the appropriate "deb-src" lines, you'll be able to easily download any source packages by running

apt-get source foo

To help you in actually building the source package, Debian source package provide the so-called build-dependencies mechanism. This means that the source package maintainer keeps a list of other packages that are required to build their package. To see how this is useful, run

apt-get build-dep foo

before building the source.

6.14 How do I build binary packages from a source package?

You will need all of foo_*.dsc, foo_*.tar.gz and foo_*.diff.gz to compile the source (note: there is no .diff.gz for some packages that are native to Debian).

Once you have them (How do I install a source package?, Section 6.13), if you have the dpkg-dev package installed, the following command:

dpkg-source -x foo_version-revision.dsc

will extract the package into a directory called foo-version.

If you want just to compile the package, you may cd into foo-version directory and issue the command

dpkg-buildpackage -rfakeroot -b

to build the package (note that this also requires the fakeroot package), and then

dpkg -i ../foo_version-revision_arch.deb

to install the newly-built package(s).

Recompile source after error

Newsgroups:  gmane.linux.debian.user
Date:        Thu, 8 Jul 2004 03:24:04 +0100 (BST)

> I was trying to compile the emacs from source deb package. The compilation
> stopped in the middle because of some error.  If I use dpkg-buildpackage,
> everything will be started all over again.  Which command I can use to
> start from where I was left?

There is a document on the debian webpage called the "Debian New Maintainers' Guide". It describes the basics of making a deb package. The part you want is the "quick rebuild" of the "build" chapter at:

http://www.debian.org/doc/maint-guide/ch-build.en.html#s-quickrebuild

"6.2 Quick rebuild

With a large package, you may not want to rebuild from scratch
every time while you tune a detail in debian/rules. For
testing purposes, you can make a .deb file without rebuilding
the upstream sources like this:

fakeroot debian/rules binary

Once you are finished with your tuning, remember to rebuild
following the above, proper procedure. You may not be able to
upload correctly if you try to upload .deb files built this
way."

Bijan Soleymani

apt-get upgrade doesn't honor my rebuilded packages

Newsgroups:  gmane.linux.debian.user
Date:        Sun, 15 Aug 2004 18:39:47 -0400

>>...
>>CVS, I needed to recompile some c++ dependent packages like fam.
>>...
>>Now if I do 'apt-get -s upgrade', I get
>>...
>>so it wants to replace it again what I just build. How can I prevent this?
>>What's puzzling me most is that this seems so a common thing to do, jet
>>I can't find this issue in the apt-howto document.
>
> FYI, I used to get this same problem while compiling sources in RH.
> I just circumvented it by increasing the version number a bit, e.g.,
>
> Current version of emacs is:
>
> emacs21_21.3+1-5
>
> I'll make it emacs21_21.3+1-5.1
>
> which was done easily with a script.
>
> I can't tell you how to do it in debian yet, because I'm new to Debian,
> and haven't been able to compile emacs (without modification) yet.

The easiest way is to do 'dch -i <comment>'/'dch -v <new-version> <comment>' from the source directory [ie the directory that contains a debian subdirectory]. dch is from package devscripts.

Alternatively, the package tools don't seem to mind if you just fudge the newest entry in debian/changelog's version up a little bit with any text editor.

Travis Crump

Prevent rebuilt packages from being upgraded

http://www.debian-administration.org/articles/332

What is the correct right way to rebuild package in Debian whilst preventing those packages from being downgraded, without applying a hold upon them?

I've increase the package version number in the packages I've rebuilt, with the intention that they will not be updated when I use "apt-get upgrade".

Unfortunately when I try this I receive the error:

The following packages will be DOWNGRADED:

dvd+rw-tools nget

What's the best approach to custom build packages so as not to interfere with upgrades?

In order not to be overwritten by apt-get, I increased my custom build packages by .1, as shown below:

$ apt-cache policy dvd+rw-tools
dvd+rw-tools:
  Installed: 5.21.4.10.8-1.1
  Candidate: 5.21.4.10.8-1

$ apt-cache policy nget
nget:
  Installed: 0.27.1-1.1
  Candidate: 0.27.1-1

But still apt-get insists that I have to downgrade them.

T Mon 16 Jan 2006

Prevent rebuilt packages from being upgraded

Hold is exactly the thing you want to do — it's designed exactly for this.

You should hold them and manually rebuild them if there's upgrade and you need it.

jooray Mon 16 Jan 2006

Prevent rebuilt packages from being upgraded

> Hold is exactly the thing you want to do -- it's designed exactly for this.

On giving it a 2nd thought, it does make sence. thanks a lot. I'll do that.

Prevent rebuilt packages from being upgraded

You may "pin" some packages (yours or those from Debian) to tell your system how to consider upgrading depending on the package origin. Pin'ing doesn't prevent upgrading, but it allows to prioritize between different apt sources, or even enforce downgrade on specific conditions. See "man apt_preferences".

progfou

Prevent rebuilt packages from being upgraded

Yes, but how do you get informed, that an updated version did get released? I get no information at all, if I pin my self-built packages…

That's why I use the +somethingN modifier on my self-built packages.

Marc

Prevent rebuilt packages from being upgraded

Using the packaging page upon the Debian server you can subscribe to new releases by email.

For example the apachetop package I maintain can be found here - with a form to the left to allow you to subscribe/unsubscribe to new releases.

Steve

Prevent rebuilt packages from being upgraded

the parent is the first post that stated the "best" (maybe not "proper") way of doing it.

actually, it depends on the circumstances which way to best keep a self-built package.

i've never had a self-built package downgraded. you probably need to pin your default distro (stable, testing, unstable, experimental) a little below the automatic install level (990?).

the problem i initially encountered was that if i rebuilt a package, keeping the same version string as the original package (by not altering the changelog), then my version on the next "apt-get upgrade" would be reinstall using the official version (but could be due to my pinning of the official repositories).

if i only wanted to keep my package installed until the next version was released (ie i didn't want to wait for a security update or bug fix to propagate to testing), i just added "0.0.1" to the debian-specific version (ie "-1" -> "-1.0.1"). normally the versioning is <upstream version>-<debian package version>.<minor package revision>, so by adding another decimal and number after the "minor package revision" i've never had a conflict. ("minor package revisions" are not regularly used except for security updates in stable, but i prefer to be safe and not increment that number.)

if i want to manage my own package regardless of newer packages then i hold the package.

echo <package> hold | dpkg --set-selections

i believe upon running "apt-get upgrade" it'll tell you which packages were not upgraded due to holds, so you'll notice when i newer version comes out (but not any subsequent newer versions).

i've found pinning to be too complex and error prone for single packages. i only pin whole distros (stable, testing, unstable) or repositories.

undefined, 16 Jan 2006