Introduction

This document describes the steps to setup a chroot environment for building Ubuntu packages using pbuilder. It is recommended for any maintainer of Ubuntu or Debian packages, or anyone interested in building packages using Ubuntu.

You can build packages without pbuilder but you must already have all the build dependencies of the package that you are building installed on your running system.

If you use LVM and want to take advantage of using LVM snapshots to speed up the chroot creation/destruction, please see SbuildLVMHowto for an alternate approach.

The following assume you want to install lucid. If you need a different release, then exchange lucid with the appropriate distribution.

The First Steps

First install the required packages.

sudo apt-get install pbuilder debootstrap devscripts

NOTE: devscripts is not necessary to install along with pbuilder, however if you are serious about using pbuilder and creating and maintaining packages for Ubuntu or Debian, you will want to install devscripts.

Create a base tarball that will contain your chroot environment to build packages with.

sudo pbuilder create

To more closely mimic the environment of the official build machines, you can use the ‘–variant=buildd’ option when creating the base tarball.

sudo pbuilder create –debootstrapopts –variant=buildd

The buildd variant will install the build-essential packages in the chroot environment, which is probably what you want, since you will be compiling packages.

Rebuilding a package

If everything went well, you should now have a tarball called base.tgz in your system under /var/cache/pbuilder.

To check if you can download source packages, you will need an uncommented deb-src line in /etc/apt/sources.list. It should look like:

deb-src http://archive.ubuntu.com/ubuntu <ubuntu_version> main restricted universe multiverse

Replace <ubuntu_version> with the version of ubuntu you are using (i.e. jaunty, karmic, or lucid). If the line above is there, but is commented out, you must uncomment it. Make sure your package index files are synchronized so that apt-get knows where to find the sources.

After you ensured the deb-src line is correct and uncommented, run:

sudo apt-get update

We will build bc, a simple calculator, from source, let’s download the debian source package (which also gets the .dsc file) from ubuntu repository:

apt-get source bc

Now build the package using your chroot cleanroom you created with the command:

sudo pbuilder build *.dsc

Once the packages are successfully built, the binary and source packages will be stored in /var/cache/pbuilder/result/

pdebuild

pdebuild is the pbuilder way of doing debuild. It comes along with the pbuilder package. pdebuild is essentially run the same way as debuild. Go into the source tree containing the debian directory and type:

pdebuild

Downloading Source Packages Using dget

There will be times when a package you want or need to build is not in the repositories of the current version of Ubuntu you are running. Rather than entering deb-src lines in your sources.list configuration for other versions of Ubuntu you are not running, you can use dget instead to download a package. dget is included in the devscripts package, hence why you should have installed it.

To use dget, first locate the .dsc file of the package you are going to build. Good places to look are http://packages.ubuntu.com/ or http://packages.debian.org/ . Once you located the .dsc file. Copy the link address to it and then in a command prompt run:

dget <link_address_to_foo.dsc>

Signing Source Files

If you intend to upload your packages to REVU, http://mentors.debian.net/, or any other location, it is highly recommended you sign your source files (.dsc and .changes files). Both REVU and http://mentors.debian.net/ enforce signed sources. The easiest way to do this after using pbuilder is by using debsign. Assuming your packages and source files were placed in /var/cache/pbuilder/result/, run;

{i} You may want to run sudo chown $USER /var/cache/pbuilder/result so that you can sign the packages.

debsign /var/cache/pbuilder/result/*.changes

NOTE: The debsign tool is part of the devscripts package mentioned previously.

If you attempted to run the debsign command as a continuation of the previous instructions for building the bc package (see “Rebuilding a package” section above), you may encounter the following error:

$ debsign bc_1.06.94-3ubuntu1_i386.changes
signfile bc_1.06.94-3ubuntu1.dsc Matthias Klose <doko@ubuntu.com>
gpg: skipped “Matthias Klose <doko@ubuntu.com>”: secret key not available
gpg: [stdin]: clearsign failed: secret key not available
debsign: gpg error occurred! Aborting….

First, keep in mind that debsign requires a PGP Key in order to create a signature for a document. If you have not already done so, you should read the GNU Privacy Guard wiki page. Even if you have created a PGP key, the command above may not work because debsign does not know what key to use. If no key is specified, the program searches through the target file (“bc_1.06.94-3ubuntu1_i386.changes” in the bc example) for the “Changed-By” field and tries to sign it using that exact UID (“Matthias Klose <doko@ubuntu.com>” in this case). Unless you are Matthias Klose, you will not be able to sign this document using that UID because you will not have the necessary private key. Instead, you must sign it using your own key by using the -k<your_own_key> command option. In the example below, the key used is “5D1AFE8F”.

$ debsign -k5D1AFE8F bc_1.06.94-3ubuntu1_i386.changes
signfile bc_1.06.94-3ubuntu1_i386.changes 5D1AFE8F

You need a passphrase to unlock the secret key for
user: “Darmeister (The DAR) <user_kp@yahoo.com>”
1024-bit DSA key, ID 5D1AFE8F, created 2009-02-03

Successfully signed dsc and changes files

If you want to save yourself the hassle of specifying the command arguments every time you run debsign, modify the configuration file(s) based on the instructions listed at the bottom of the debsign manpage (see below). Set DEBSIGN_PROGRAM=gpg, DEBSIGN_SIGNLIKE=gpg and DEBSIGN_KEYID=5D1AFE8F in one of the configurations files. This will provide the necessary parameters for debsign to execute properly.

CONFIGURATION VARIABLES
The two configuration files /etc/devscripts.conf and ~/.devscripts are
sourced in that order to set configuration variables. Command line
options can be used to override configuration file settings. Environ‐
ment variable settings are ignored for this purpose. The currently
recognised variables are:

DEBSIGN_PROGRAM
Setting this is equivalent to giving a -p option.

DEBSIGN_SIGNLIKE
This must be gpg or pgp and is equivalent to using either -sgpg
or -spgp respectively.

DEBSIGN_MAINT
This is the -m option.

DEBSIGN_KEYID
And this is the -k option.

Updating a chroot

It is recommended you update your chroot daily before each build, to do this task use the command below:

sudo pbuilder update

Updating a chroot to another version of ubuntu

For new packages you need a chroot of the current distribution under development of Ubuntu (hardy, at this writing). To do so, create a pbuilder chroot as usual and then do:

sudo pbuilder update –distribution DIST-NAME –override-config

It will update the chroot to the DIST-NAME version of ubuntu and will override the configuration files to make it effective. Then you can start building packages for the next version of ubuntu.

Speeding up build-dependency calculation

If you use feisty you can use a new build-dependency resolver based on gdebi that should be significantly faster. Change ~/.pbuilderrc to add this line:

PBUILDERSATISFYDEPENDSCMD=”/usr/lib/pbuilder/pbuilder-satisfydepends-gdebi”

Problems with pbuilder-satisfydepends-gdebi and local repositories

If you are using a local overlay repository (a very advanced use of pbuilder usually used for backport archives), you will likely want to use a modified version of ‘pbuilder-satisfydepends-gdebi’. First, copy the dependency resolver over, and mark it as executable.

cp /usr/lib/pbuilder/pbuilder-satisfydepends-gdebi ~/.pbuilder-satisfydepends-gdebi
chmod +x ~/.pbuilder-satisfydepends-gdebi

Change line 80 of ‘$HOME/.pbuilder-satisfydepends-gdebi’ to ignore warnings from local packages that aren’t in the Ubuntu keyring.

Change:

$CHROOTEXEC /usr/bin/apt-get install -y $INSTALL

To this:

$CHROOTEXEC /usr/bin/apt-get install -y –force-yes $INSTALL

Then change ~/.pbuilderrc to use your local modified dependency resolver script instead of the one which comes with pbuilder by default:

PBUILDERSATISFYDEPENDSCMD=”~/.pbuilder-satisfydepends-gdebi”

Integration with ccache

Using ccache with pbuilder is easy, simply add the following to ~/.pbuilderrc (/etc/pbuilder/pbuilderrc is an alternative):

# ccache
sudo mkdir -p /var/cache/pbuilder/ccache
sudo chmod a+w /var/cache/pbuilder/ccache
export CCACHE_DIR=”/var/cache/pbuilder/ccache”
export PATH=”/usr/lib/ccache:${PATH}”
EXTRAPACKAGES=ccache
BINDMOUNTS=”${CCACHE_DIR}”

Now pbuilder will automatically cache compiler output between multiple builds of the same software.

Universe support

If you want to rebuild a package from universe or build a new one that needs a package out of main you will need to add this to ~/.pbuilderrc:

COMPONENTS=”main restricted universe multiverse”

if [ “$DIST” == “lenny” ]; then
echo “Using a Debian pbuilder environment because DIST is $DIST”
COMPONENTS=”main contrib non-free”
fi

After adding the new sources you need to update the chroot, so that it picks up the new apt lines:

sudo pbuilder update –override-config

Building an i386 pbuilder on AMD64

One of the things a pbuilder is useful for is building i386 packages on an AMD64 machine. You can create an i386 chroot with the command:

sudo pbuilder create –debootstrapopts –arch –debootstrapopts i386

If you’re interested in using pbuilder to build on other architectures, you should read the next section on multiple pbuilders.

Multiple pbuilders

When you work with packages, you often want to have multiple pbuilders on your machine, if for example you want to backport to Dapper while developing on the development version of Ubuntu (currently Intrepid). Or maybe you want to build your packages for Debian and have them merged back to Ubuntu. The next sections will provide some information to get you started with using multiple pbuilders.

Update debootstrap

It is recommended to use an updated version of debootstrap from the backports repository of whatever version of Ubuntu you are using. You can either activate the backports repository in your sources.list configuration or download the source package using dget, build the packages, and install them. The updated version will have support for newer distributions, such as the development branch of Ubuntu.

Change base.tgz Location

The only thing required to use pbuilder with multiple distributions is an alternate location to store the gzipped tarball that contains the pbuilder environment. On the command line, this can be specified with the ‘basetgz’ option. However, it is tedious to specify the full path every time pbuilder is run, so it is convenient to place a snippet in ~/.pbuilderrc to automate this:

# Codenames for Debian suites according to their alias. Update these when
# needed.
UNSTABLE_CODENAME=”sid”
TESTING_CODENAME=”squeeze”
STABLE_CODENAME=”lenny”
STABLE_BACKPORTS_SUITE=”$STABLE_CODENAME-backports”

# List of Debian suites.
DEBIAN_SUITES=($UNSTABLE_CODENAME $TESTING_CODENAME $STABLE_CODENAME
“unstable” “testing” “stable”)

# List of Ubuntu suites. Update these when needed.
UBUNTU_SUITES=(“maverick” “lucid” “karmic” “jaunty” “hardy”)

# Mirrors to use. Update these to your preferred mirror.
DEBIAN_MIRROR=”ftp.us.debian.org”
UBUNTU_MIRROR=”mirrors.kernel.org”

# Optionally use the changelog of a package to determine the suite to use if
# none set.
if [ -z “${DIST}” ] && [ -r “debian/changelog” ]; then
DIST=$(dpkg-parsechangelog | awk ‘/^Distribution: / {print $2}’)
# Use the unstable suite for certain suite values.
if $(echo “experimental UNRELEASED” | grep -q $DIST); then
DIST=”$UNSTABLE_CODENAME”
fi
fi

# Optionally set a default distribution if none is used. Note that you can set
# your own default (i.e. ${DIST:=”unstable”}).
: ${DIST:=”$(lsb_release –short –codename)”}

# Optionally change Debian release states in $DIST to their names.
case “$DIST” in
unstable)
DIST=”$UNSTABLE_CODENAME”
;;
testing)
DIST=”$TESTING_CODENAME”
;;
stable)
DIST=”$STABLE_CODENAME”
;;
esac

# Optionally set the architecture to the host architecture if none set. Note
# that you can set your own default (i.e. ${ARCH:=”i386″}).
: ${ARCH:=”$(dpkg –print-architecture)”}

NAME=”$DIST”
if [ -n “${ARCH}” ]; then
NAME=”$NAME-$ARCH”
DEBOOTSTRAPOPTS=(“–arch” “$ARCH” “${DEBOOTSTRAPOPTS[@]}”)
fi
BASETGZ=”/var/cache/pbuilder/$NAME-base.tgz”
# Optionally, set BASEPATH (and not BASETGZ) if using cowbuilder
# BASEPATH=”/var/cache/pbuilder/$NAME/base.cow/”
DISTRIBUTION=”$DIST”
BUILDRESULT=”/var/cache/pbuilder/$NAME/result/”
APTCACHE=”/var/cache/pbuilder/$NAME/aptcache/”
BUILDPLACE=”/var/cache/pbuilder/build/”

if $(echo ${DEBIAN_SUITES[@]} | grep -q $DIST); then
# Debian configuration
MIRRORSITE=”http://$DEBIAN_MIRROR/debian/&#8221;
COMPONENTS=”main contrib non-free”
# This is for enabling backports for the Debian stable suite.
if $(echo “$STABLE_CODENAME stable” | grep -q $DIST); then
EXTRAPACKAGES=”$EXTRAPACKAGES debian-backports-keyring”
OTHERMIRROR=”$OTHERMIRROR | deb http://www.backports.org/debian $STABLE_BACKPORTS_SUITE $COMPONENTS”
fi
elif $(echo ${UBUNTU_SUITES[@]} | grep -q $DIST); then
# Ubuntu configuration
MIRRORSITE=”http://$UBUNTU_MIRROR/ubuntu/&#8221;
COMPONENTS=”main restricted universe multiverse”
else
echo “Unknown distribution: $DIST”
exit 1
fi

NOTE: There are some optional lines in this snippet that appear after comments that start with “Optionally”. Either comment these lines out or change the lines to suit your needs.

Now, if the user sets DIST to another distribution such as hardy when running pbuilder, the tarball location will be changed. The line that sets the DISTRIBUTION only takes effect during the creation of a new base tarball, or if the –override-config option is given, where it specifies the distribution to use for the new base tarball. Setting BUILDRESULT or APTCACHE is optional, but possibly helpful.

If ARCH is set to a different architecture when running pbuilder, pbuilder will be set to create an environment to build packages for the architecture specified in ARCH.

We can now create and use alternate tarballs, as in the following examples:

# Create a base environment for Ubuntu hardy
sudo DIST=hardy pbuilder create

# Create a base environment for Debian sid
sudo DIST=sid pbuilder create

# Create a base environment for Ubuntu hardy under
# the i386 architecture
sudo DIST=hardy ARCH=i386 pbuilder create

# Update a base environment for Ubuntu hardy
sudo DIST=hardy pbuilder update

# Build a package using Ubuntu hardy as the base
# environment
DIST=hardy pdebuild

# Build a package using Ubuntu hardy as the base
# environment under the i386 architecture
DIST=hardy ARCH=i386 pdebuild

Using backport repositories in pbuilder

Debian

By default, no packages from backports.org is automatically installed. You will need to set your /etc/apt/preferences in your chroot to enable packages to be automatically installed from the backports suite. This can be achieved using pbuilder hooks.

First, you must create and then specify the location of the hooks directory via the HOOKDIR variable in your ~/.pbuilderrc script. For example, if you created a hooks directory under /var/cache/pbuilder/hook.d, then you should place the following in your ~/.pbuilderrc script.

HOOKDIR=”/var/cache/pbuilder/hook.d/”

Then write a script under /var/cache/pbuilder/hook.d that will write the preferences file in your chroot. The script name must be of the form ‘E<digit><digit><whatever else you want>’.

For example, a script can be saved to /var/cache/pbuilder/hook.d/E01apt-preferences and written like so.

#!/bin/sh
set -e

STABLE_VERSION_REGEX=’^5\.0\.[0-9]\+$’

if $(cat “/etc/debian_version” | grep -q -e “$STABLE_VERSION_REGEX”); then
cat > “/etc/apt/preferences” << EOF
Package: debhelper
Pin: release a=lenny-backports
Pin-Priority: 999

Package: lintian
Pin: release a=lenny-backports
Pin-Priority: 999
EOF
fi

Note that the only packages specified here are debhelper and lintian. More can be specified, although these are two common ones to backport. You should keep packages that are backported for your pbuilder environment at a minimum.

Using the ‘othermirror’ option

It is possible to specify more mirrors than the one specified for MIRRORSITE. There’s two ways to do this, specifiying the option ‘–othermirror “<sources.list deb line>”‘ when running pbuilder, or using the variable ‘OTHERMIRROR=”<sources.list deb line>”‘ in the pbuilderrc configuration file. Just replace “<sources.list deb line>” with a deb line in the same format as would be found under /etc/apt/sources.list.

Note: Don’t forget to use –override-config and then pbuilder update to take the new repository into account.

Troubleshooting “pbuilder create”

Make sure that you have debootstrap later than X installed. The version from hardy will not suffice. Install from backports or backport yourself if necessary.

If you are running pbuilder < 0.196, then you will encounter this error when you try to create a base tarball for sid:

chroot: cannot run command `/usr/bin/apt-get’: No such file or directory

This was fixed in pbuilder 0.196. To workaround this on older versions of pbuilder, you will need to add this line to your ~/.pbuilderrc

DEBOOTSTRAPOPTS=(“–include=apt” “${DEBOOTSTRAPOPTS[@]}”)

There will be sometimes where running sudo pbuilder create will fail to create a base tarball. This normally occurs only when creating base tarballs for development versions of Ubuntu or Debian (for example, Debian sid). These are development versions and it is best to wait and try at a later date to create a base tarball. It can be days however (sometimes weeks) until creating a base tarball will be successful for these development versions. In the meantime you could create a base tarball for an older version of Ubuntu or Debian and update the tarball to the development version instead.

For example, to create an etch base tarball and update to sid, start with:

sudo DIST=etch pbuilder create

Then to update, run:

sudo DIST=etch pbuilder update –override-config \
–othermirror “deb http://http.us.debian.org/debian sid main”

What will happen is that the base packages for Etch will be downloaded, installed, and configured first. Then apt-get update will be performed for “etch main” and “sid main”. When the update is run, all packages in need of upgrading will be upgraded and thus, the base packages for Sid will be installed. After pbuilder is done, a base tarball will have been created but named for Etch (etch-base.tgz). All the base packages will be copied into the aptcache directory in /var/cache/pbuilder/etch. From here you can copy the aptcache directory over to the sid directory and make a copy of etch-base.tgz and call it sid-base.tgz.

sudo mkdir /var/cache/pbuilder/sid
sudo cp /var/cache/pbuilder/etch/aptcache /var/cache/pbuilder/sid/aptcache
sudo cp /var/cache/pbuilder/etch-base.tgz /var/cache/pbuilder/sid-base.tgz

It is better of course to create a base tarball directly. Check often to see if a base tarball can be created directly.

Building With Local Packages

Sometimes a package you intend to build will depend on a recent version of a package that isn’t found in the Ubuntu or Debian archives. Or your package depends on another package that isn’t in the Ubuntu or Debian archives at all. For these type of cases, you could create the packages and upload them to your local filesystem as you wait for a package to be uploaded to the archives. The next sections will cover setting up a miniature repository on your system for use with pbuilder.

Setting up

First, install the required packages.

sudo apt-get install dput mini-dinstall

Create a file call .mini-dinstall.conf under your home directory with the following contents:

[DEFAULT]
architectures = all, i386, amd64, powerpc
archivedir = /var/cache/archive/
use_dnotify = 0
verify_sigs = 0
extra_keyrings = ~/.gnupg/pubring.gpg
mail_on_success = 0
archive_style = flat
poll_time = 10
mail_log_level = NONE

[sid]

[etch]

[hardy]

This conffile was modified from the documentation for mini-dinstall (/usr/share/doc/mini-dinstall). Under architectures, you can choose to only specify the architecture of your machine. The listing of [sid], [hardy], etc. is so that you will be able to upload packages using dput for Debian sid or any Ubuntu version. If you are only building packages for one version, just list only that version.

Edit the [local] stanza under ~/.dput.cf (/etc/dput.cf is an alternative) to look like:

[local]
method = local
incoming = /var/cache/archive/mini-dinstall/incoming
allow_non-us_software = 1
run_dinstall = 0
post_upload_command = mini-dinstall –batch

Now create the “incoming” directory for your local repository and set yourself as the owner.

sudo mkdir -p /var/cache/archive/mini-dinstall/incoming
sudo chown -R $USER /var/cache/archive/

Uploading to Local Filesystem

Once you build a package, you can upload it to your local filesystem. Run:

dput local foo*.changes

With the configuration above, it should end up in

/var/cache/archive/<distro-version>

<distro-version> is either sid, hardy, etc. depending on what distro version you built the package for. In this directory, there should be a Packages and Source file along with the packages you uploaded.

Updating Using the Local Repository

Rewrite your pbuilderrc configuration file to place a snippet to look like this.

# Codenames for Debian suites according to their alias. Update these when
# needed.
UNSTABLE_CODENAME=”sid”
TESTING_CODENAME=”squeeze”
STABLE_CODENAME=”lenny”
STABLE_BACKPORTS_SUITE=”$STABLE_CODENAME-backports”

# List of Debian suites.
DEBIAN_SUITES=($UNSTABLE_CODENAME $TESTING_CODENAME $STABLE_CODENAME
“unstable” “testing” “stable”)

# List of Ubuntu suites. Update these when needed.
UBUNTU_SUITES=(“lucid” “karmic” “jaunty” “intrepid” “hardy”)

# Mirrors to use. Update these to your preferred mirr

Iklan