path: root/Documentation/pbuilder-doc.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "/usr/share/sgml/docbook/dtd/xml/4.2/docbookx.dtd"> 
<!-- the original of this documentation is in pbuilder source tar-ball,
  and the latest version is found in CVS repository. -->
<book>
  <bookinfo>
    <date>2003-03-01</date>
    <title>pbuilder User's Manual</title>
    <abbrev>pbuilder-doc</abbrev>
    <subtitle>Usage and operations</subtitle>
    <releaseinfo>documentation in progress</releaseinfo>
    <authorgroup>
      <author>
	<firstname>Junichi</firstname>
	<surname>Uekawa</surname>
      </author>
    </authorgroup>
  </bookinfo>
  <chapter>
    <title>Introducing pbuilder</title>
    <sect1 id="aim">
      <title>Aims of pbuilder</title>
      <para>
	<command>pbuilder</command> stands for 
	Personal Builder, and it is a automatic Debian Package Building system
	for personal environments.
	<command>pbuilder</command> aims to be an 
	easy-to-setup system
	for auto-building Debian packages inside a clean-room
	environment, so that it is possible to verify that
	a package can be built on most Debian installations.
	Clean-room environment is achieved through use of a chroot image,
	so that only minimal packages will be installed inside the
	chroot.
      </para>
      <para>
	Debian distribution consists of free software
	accompanied with source.
	The source code within Debian "main" section
	must build within Debian "main",
	with only the explicitly specified build-dependencies
	installed.
      </para>
      <para>
	The primary aim of pbuilder is different from other 
	auto-building systems in Debian by the fact that its aim is not in trying to build
	as many packages. 
        It does not try to guess
	what a package needs, and in most cases it tries the
	worst choice of all if there was a choice to be made.
      </para>
      <para>
	In this way, <command>pbuilder</command> tries to ensure 
	that packages 
	tested against pbuilder will build properly in 
	most Debian installations, hopefully resulting
	in a good overall Debian source-buildability.
      </para>
      <para>
	The goal of making Debian buildable from source is 
	somewhat achieved, and has seen a good progress.
	It is known that Debian 3.0 is not quite 
	buildable from source, but the next version should 
	be better, and the version after.
      </para>
    </sect1>
  </chapter>
  <chapter id="usingpbuilder">
    <title>Using pbuilder</title>
    <sect1 id="creatingbase">
      <title>Creating base chroot image</title>
      <para>
	<command>pbuilder create</command>
	will create base chroot image.
	Distribution code-name needs to be specified with 
	<command><option>--distribution</option></command>
	command-line option.
	Usually, "sid" is used.
      </para>
      <para>
	<command>debootstrap</command> is used to create 
	the bare minimum Debian installation, 
	and then build-essential packages are installed on top 
	of the minimum installation using <command>apt-get</command> 
	inside the chroot.
      </para>
      <para>
	For fuller documentation of command-line options, see
	pbuilder.8 manual page.
	Some configuration will be required for <filename>/etc/pbuilderrc</filename>
	for the mirror site
	<footnote>
	  <para>
	    The mirror site should preferably a local mirror or a cache server,
	    to not to overload the public mirrors with
	    a lot of access.
	    Use of tools such as apt-proxy would be advisable.
	  </para>
	</footnote>
	to use, and proxy configuration may be required to allow access
	through HTTP.
	See pbuilderrc.5 manual page for details.
      </para>
    </sect1>
    <sect1>
      <title>Updating base chroot image</title>
      <para><command>pbuilder update</command>
	will update the chroot image.
	It will extract the chroot, invoke <command>apt-get update</command>
	and <command>apt-get dist-upgrade</command> inside the 
	chroot, and then recreate the base tarball.
      </para>
      <para>
	It is possible to switch the distribution which the chroot 
	tarball is targeted at at this point.
	Specify <command><option>--distribution <parameter>sid</parameter></option> <option>--override-config</option></command> to change the distribution
	to sid.
	<footnote>
	  <para>Only upgrading is supported.</para>
	</footnote>
      </para>
      <para>
	For fuller documentation of command-line options, see
	pbuilder.8 manual page
      </para>
    </sect1>
    <sect1 id="buildpackagechroot">
      <title>Building a package using chroot image</title>
      <para>
	To build a package inside the chroot, invoke
	<command>pbuilder build <option>whatever.dsc</option></command>.
	<command>pbuilder</command> will extract 
	chroot image to a temporal working directory,
	and satisfy the build-dependency inside the chroot,
	and build the package.
	The built packages will be moved to a 
	directory specified with 
	<command><option>--buildresult</option></command>
	command-line option.
      </para>
      <para>
	<command><option>--basetgz</option></command> option can be 
	used to specify which chroot image to use.
      </para>
      <para>
	<command>pbuilder</command> will extract a fresh chroot image
	created with <command>pbuilder build</command>
	and updated with <command>pbuilder update</command>,
	and populate the chroot with build-dependency by parsing 
	debian/control and invoking <command>apt-get</command>.
      </para>
      <para>
	For fuller documentation of command-line options, see
	pbuilder.8 manual page
      </para>
    </sect1>
    <sect1 id="pdebuild">
      <title>Facilitating Debian Developers' typing, pdebuild</title>
      <para>
	<command>pdebuild</command> is a little wrapper 
	script that does the most frequent of all tasks.
	A Debian Developer may try to do <command>debuild</command>, and 
	build a package, inside a Debian source directory.
	<command>pdebuild</command> will allow similar 
	control, and allow package to be built inside the chroot,
	to check that the current source tree will build happily
	inside the chroot.
      </para>
      <para>
	<command>pdebuild</command> calls <command>dpkg-source</command>
	to build the source packages, and then invoke
	<command>pbuilder</command> on the resulting source package.
	However, unlike debuild, the resulting deb files will be
	found somewhere in BUILDRESULT directory.
      </para>
      <para>
	See pdebuild.1 manual page for more details.
      </para>
      <para>
	There is a slightly different mode of operation available 
	to pdebuild since version 0.97. pdebuild usually runs <command>debian/rules clean</command> outside of chroot, however, it is possible to change the behavior to run it inside chroot with <command><option>--use-pdebuild-internal</option></command>.
	It will try to bind mount the working directory inside chroot, 
	and run <command>dpkg-buildpackage</command> inside.
	It has the following characteristics, and thus cannot be made default.
      </para>
      <itemizedlist>
	<listitem>
	  <para>The working directory is modified from inside chroot</para>
	</listitem>
	<listitem>
	  <para>Building with pdebuild does not guarantee that it works with pbuilder</para>
	</listitem>
	<listitem>
	  <para>If making source package fails, the chroot session is wasted</para>
	</listitem>
	<listitem>
	  <para>Does not work in the same manner as it used to, such as --buildresult does not have an effect</para>
	</listitem>
      </itemizedlist>

    </sect1>
    <sect1 id="configfile">
      <title>Configuration Files</title>
      <para>
	It is possible to specify all settings by command-line
	option. However, for typing convenience it is possible to 
	use a configuration file.
      </para>
      <para>
	<filename>/etc/pbuilderrc</filename> and 
	<filename>${HOME}/.pbuilderrc</filename>
	are read in when pbuilder is invoked.
	The possible options are documented in 
	pbuilderrc.5 manual page.
      </para>
      <para>
	It is useful when switching between configuration files for 
	different distributions.
      </para>
    </sect1>
    <sect1 id="nonrootchroot">
      <title>Building packages as non-root inside the chroot</title>
      <para>
	<command>pbuilder</command> requires full root privilege 
	when it is satisfying the build-dependency but most packages do not 
	need root privilege, or fail to build when they are root.
	<command>pbuilder </command> can create a user which is only used 
	inside <command>pbuilder </command> and use that user id when
	building, and use <command>fakeroot</command> command
	when root privilege is required.
      </para>
      <para>
	BUILDUSERID should be set to a value for a user id that
	does not already exist on the system, so that it is more difficult for 
	packages that are being built with 
	<command>pbuilder</command> to affect the environment outside the chroot.
	When BUILDUSERNAME is also set,  
	pbuilder will use that user id and fakeroot for building packages.
      </para>
      <para>
	Using the fakerooting method, pbuilder will run with 
	root privilege when it is required, when installing
	packages to the chroot.
      </para>
      <para>
	To be able to invoke pbuilder without being 
	root, you need to use user-mode-linux, as explained
	in <xref linkend="pbuilder-uml"/>.
      </para>
    </sect1>
    <sect1 id="backporting">
      <title>Using pbuilder for back-porting</title>
      <para>
	pbuilder can be used for back-porting software from 
	the latest Debian distribution to 
	older stable distribution, by using a chroot that contains
	image of older distribution, and building packages inside the
	chroot.
	There are several points to consider, and due to the following reasons,
	automatic back-porting is usually not possible, and 
	manual interaction is required:
      </para>
      <itemizedlist>
	<listitem>
	  <para>Build-Dependency in stable may not be enough to build a package in unstable distribution, so package may need more than what exists in stable</para>
	</listitem>
	<listitem>
	  <para>Stable distribution may have bugs that have been fixed in unstable that needs to be worked around.</para></listitem>
	<listitem>
	  <para>Package in unstable distribution may have problem building even for unstable.</para>
	</listitem>
      </itemizedlist>
    </sect1>
    <sect1 id="massbuild">
      <title>Mass-building packages</title>
      <para>
	pbuilder can be automated, because its operations are
	non-interactive.
	It is possible to run pbuilder through multiple packages 
	non-interactively.
	There are several such scripts known to exist.
	Junichi Uekawa has been running such script since 2001,
	and has been filing bugs on packages that fail the 
	test of pbuilder. There were several problems with auto-building:
      </para>
      <itemizedlist>
	<listitem>
	  <para>Build-Dependency needs to install non-interactively, but 
	    some packages are so broken that they cannot install 
	    without interaction (like postgresql)</para>
	</listitem>
	<listitem>
	  <para>When a library package breaks, or gcc/gcj/g++ breaks, 
	    or even bison, a large number of build failure are reported.
	    (gcj-3.0 which had no "javac", bison which got more strict, etc.)
	  </para>
	</listitem>
	<listitem>
	  <para>Some people were quite hostile against build failure reports.</para>
	</listitem>
      </itemizedlist>
      <para>
	But most of these problems are now getting solved.
	Only about 10% of Debian now fail to build from source (29 Dec 2002).
      </para>
      <para>
	A script that was used by Junichi Uekawa is now included in 
	pbuilder distribution, as <command>pbuildd.sh</command>.
	It is available in <filename>/usr/share/doc/pbuilder/examples/pbuildd/</filename>
	and its configuration is in <filename>/etc/pbuilder/pbuildd-config.sh</filename>.
	It should be easy enough to set up for people who are used to 
	pbuilder. It has been running for quite a while, and it should be 
	possible to set the application up on your system also.
	However, it is a new introduction, and please file bugs
	to the Debian BTS if you know of possible problems,
	or improved on the script considerably.
      </para>
      <para>
	To set up pbuildd, there are some points to be aware of.
      </para>
      <itemizedlist>
	<listitem>
	  <para>A file <filename>./avoidlist</filename> needs to be available with the list of packages to avoid building. </para>
	</listitem>
	<listitem>
	  <para>It will try building anything, even packages that are not aimed for your architecture</para>
	</listitem>
	<listitem>
	  <para>Because you are running random build scripts, it is better to use 
	  fakeroot option of pbuilder, to avoid running build in root privilege</para>
	</listitem>
	<listitem>
	  <para>Because not all builds are guaranteed to finish in a finite time,
	    setting timeout is probably necessary, or build may stall with
	    a bad build</para>
	</listitem>
	<listitem>
	  <para>
	    Some packages require a lot of disk space, 
	    around 2GB seems to be sufficient for the largest packages for the time being.
            If you find it otherwise, please inform the maintainer of this documentation.
	  </para>
	</listitem>
      </itemizedlist>
    </sect1>
    <sect1>
      <title>Auto-backporting scripts</title>
      <para>
	There are some people who use pbuilder to automatically back-port
	a subset of packages to the stable distribution.
      </para>
      <para>
	I would like some information on how people are doing it,
	I would appreciate any feedback or information on 
	how you are doing, or any examples.
      </para>
    </sect1>
    <sect1 id="autotesting">
      <title>Using pbuilder for automated testing of packages</title>
      <para>
	pbuilder can be used for automated testing of packages.
	It has the feature of allowing hooks to be placed,
	and these hooks can try to install packages inside
	the chroot, or run them, or whatever else that 
	can be done. Some known tests and ideas:
      </para>
      <itemizedlist>
	<listitem>
	  <para>Automatic install-remove-upgrade-remove-install-purge-upgrade-purge testsuite (distributed as an example, <filename>B91dpkg-i</filename>), 
	    or just check that everything installs somewhat (<filename>execute_installtest.sh</filename></para>
	</listitem>

	<listitem>
	  <para>Automatically running lintian/linda (distributed as an example in
	    <filename>/usr/share/doc/pbuilder/examples/B90linda</filename>)</para>
	</listitem>
	<listitem>
	  <para>Automatic debian-test of the package? debian-test package has been removed from Debian.</para>
	</listitem>
     </itemizedlist>
    </sect1>
    <sect1 id="altcompiler">
      <title>Using pbuilder for testing build with alternate compilers</title>
      <para>
	Most packages are compiled with <command>gcc</command> 
	or <command>g++</command>
	and using the default compiler version, which was gcc 2.95 for Debian GNU/Linux 3.0 (i386).
	However, Debian 3.0 was distributed with other compilers, under package names
        such as <command>gcc-3.2</command> for gcc compiler 
	version 3.2.
	It was therefore possible to try compiling packages against different
	compiler versions.
	<command>pentium-builder</command> provides an infrastructure for 
	using different compiler for building packages than the default gcc, by
	becoming a wrapper script called gcc, that calls the real gcc.
	To use <command>pentium-builder</command> in <command>pbuilder</command>, it is possible to set up the
	following in the configuration:
	<screen>
EXTRAPACKAGES="pentium-builder gcc-3.2 g++-3.2"
export DEBIAN_BUILDARCH=athlon
export DEBIAN_BUILDGCCVER=3.2
	</screen>
      </para>
      <para>
	It will instruct <command>pbuilder</command> to install <command>pentium-builder</command> package 
	and also the GCC 3.2 compiler packages inside the chroot,
	and set the environment variables required for 
	<command>pentium-builder</command> to function.
      </para>
    </sect1>
  </chapter>

  <chapter id="pbuilder-uml">
    <title>Using User-mode-linux with pbuilder</title>
    <para>
      <command>pbuilder-uml</command> exists.
      Invoking that command instead of <command>pbuilder</command>
      it is possible to use user-mode-linux.
      The advantage of using user-mode-linux is that 
      it does not require root privilege to run,
      and it does Copy-on-write, which is probably  much faster than
      conventional pbuilder method.
    </para>
    <para>
      The problem is that this relies on User-mode-linux
      which is a relatively new project, and has not quite
      matured, as opposed to conventional pbuilder which rely 
      on <command>chroot</command> and <command>tar</command> 
      and <command>gzip</command>, which are known to work
      on most Unix systems.
      However, <command>pbuilder-uml</command>  uses COW method for 
      file access, and it is so much more faster than pbuilder 
      when building most packages.
    </para>
    <para>
      It has been verified that pbuilder-uml works,
      as of version 0.59.
      And since then, pbuilder-uml has seen a rapid evolution.
      The configuration of pbuilder-uml goes in three steps:
      <itemizedlist>
	<listitem>
	  <para>Configuration of user-mode-linux</para>
	</listitem>
	<listitem>
	  <para>Configuration of rootstrap</para>
	</listitem>
	<listitem>
	  <para>Configuration of pbuilder-uml</para>
	</listitem>
      </itemizedlist>
    </para>
    <sect1 id="user-mode-linux-config">
      <title>Configuring user-mode-linux</title>
      <para>
	<command>user-mode-linux</command> requires 
	the user to be in uml-net group in order to configure the network 
	unless you are using slirp.
	Read <filename>/usr/share/doc/uml-utilities/README.Debian</filename>
	for details.
      </para>
    </sect1>
    <sect1 id="rootstrap">
      <title>Configuring rootstrap</title>
      <para>
	<command>rootstrap</command> is a program that 
	is a wrapper to debootstrap, creating a Debian disk image inside
	UML.
	To configure rootstrap, there are several requirements.
      </para>
      <itemizedlist>
	<listitem>
	  <para>install rootstrap package</para>
	</listitem>
	<listitem>
	  <para>
	    TUN/TAP only: 
	    add the user to uml-net group to allow access to network
	    <screen>
adduser dancer uml-net
	    </screen></para>
	</listitem>
	<listitem>
	  <para>TUN/TAP only: 
	    Check that compile supports tun/tap interface,
	    and recompile the kernel if necessary
	  </para>
	</listitem>
	<listitem>
	  <para>Set up /etc/rootstrap/rootstrap.conf, for example,
	    if the current host is 192.168.1.2, changing following 
	    entries to something like this seems to work.
	    <screen>
transport=tuntap
interface=eth0
gateway=192.168.1.1
mirror=http://192.168.1.2:8081/debian
host=192.168.1.198
uml=192.168.1.199
netmask=255.255.255.0
	    </screen>
	    Some experimentation with configuration and running
	    <command>rootstrap ~/test.uml</command> to actually 
	    test it would be handy.
	  </para>
	  <para>
	    Using slirp requires less configuration. 
	    The default configuration comes with a working example.
	  </para>
	</listitem>
      </itemizedlist>
    </sect1>
    <sect1 id="pbuilderumlconfig">
      <title>Configuring pbuilder-uml</title>
      <para>
	The following needs to happen:
	<itemizedlist>
	  <listitem>
	    <para>install pbuilder-uml package</para>
	  </listitem>
	  <listitem>
	    <para>
	      Set configuration file <filename>/etc/pbuilder/pbuilder-uml.conf</filename> in the following manner. It will be different for slirp.
	      <screen>
MY_ETH0=tuntap,,,192.168.1.198
UML_IP=192.168.1.199
UML_NETMASK=255.255.255.0
UML_NETWORK=192.168.1.0
UML_BROADCAST=255.255.255.255
UML_GATEWAY=192.168.1.1
PBUILDER_UML_IMAGE="/home/dancer/uml-image"
	      </screen>
	      and it needs to match rootstrap configuration.
	    </para>
	  </listitem>
	  <listitem>
	    <para>
	      Make sure BUILDPLACE is writable by the user.
	      Change BUILDPLACE in the configuration file to a place
	      where the user can access.
	    </para>
	  </listitem>
	  <listitem>
	    <para>Run <command>pbuilder-user-mode-linux create --distribution sid</command> to create the image</para>
	  </listitem>
	  <listitem>
	    <para>Try running <command>pbuilder-user-mode-linux build </command></para>
	  </listitem>
	</itemizedlist>
      </para>
    </sect1>
    <sect1 id="consideruml">
      <title>Considerations for running pbuilder-uml</title>
      <para>
	pbuilder-user-mode-linux emulates most of pbuilder, but there
	are some differences.
      </para>
      <itemizedlist>
	<listitem>
	  <para>	  
	    pbuilder-user-mode-linux does not support all options of pbuilder
	    properly yet. This is a problem, and will be addressed as 
	    specific areas are discovered.
	  </para>
	</listitem>
	<listitem>
	  <para>
	    /tmp is handled differently inside pbuilder-uml.
	    In pbuilder-uml, /tmp is mounted as tmpfs inside UML,
	    so accessing files under /tmp from outside the user-mode-linux
	    does not work.
	    It affects options like
	    <command><option>--configfile</option></command>,
	    and when trying to build packages placed under <filename>/tmp</filename>.
	  </para>
	</listitem>
      </itemizedlist>
    </sect1>
    <sect1 id="paralleluml">
      <title>Parallel running of pbuilder-user-mode-linux</title>
      <para>
	To run pbuilder-uml parallel on a system, there are a few things 
	to bear in mind.
      </para>
      <itemizedlist>
	<listitem>
	  <para>create and update methods must not be ran when build is in progress, or COW file will be invalid</para>
	</listitem>
	<listitem>
	  <para>
	    If you are not using slirp, UML processes that are running in parallel needs to have 
	    different IP addresses.
	    So, something like the following will work, 
	    <command>for IP in 102 103 104 105; do xterm -e  pbuilder-user-mode-linux build --uml-ip 192.168.0.$IP 20030107/whizzytex_1.1.1-1.dsc&amp; done 
	    </command>
	    but just trying to run <command>pbuilder-uml</command> 
	    several times will result in failure to access the network.
	    When using slirp, this problem does not exist.
	  </para>
	</listitem>
      </itemizedlist>
    </sect1>
    <sect1 id="pbuilderumlwrap">
      <title>Using pbuilder-uml as a wrapper script to start up virtual machine</title>
      <para>
	It is possible to use pbuilder-uml for other uses than just building Debian 
	packages.
	<command>pbuilder-user-mode-linux login</command>
	will let a user use a shell inside the user-mode-linux using the 
	pbuilder base image,
	and <command>pbuilder-user-mode-linux execute</command> will
	allow the user to execute a script inside the chroot.
      </para>
      <para>
	You can use the script to install ssh and add a new user,
	so that it is possible to access inside the UML through ssh.
      </para>
      <para>
	Note that it is not possible to use a script from 
	<filename>/tmp</filename> due to the way pbuilder-uml mounts 
	tmpfs at <filename>/tmp</filename>.
      </para>
      <para>
	The following is an example script  that may be useful in starting a sshd 
	inside uml.
      </para>
      <screen>
#!/bin/bash

apt-get install -y ssh xbase-clients xterm
echo "enter root password"
passwd 
cp /etc/ssh/sshd_config{,-}
cat /etc/ssh/sshd_config- | sed 's/X11Forwarding.*/X11Forwarding yes/' &gt; /etc/ssh/sshd_config

/etc/init.d/ssh restart
ifconfig
echo "Hit enter to finish"
read
      </screen>
    </sect1>
  </chapter>
  <chapter id="faq">
    <title>Frequently asked questions </title>
    <!-- Start of FAQ -->
    <para>
      Here, known problems and frequently asked questions are
      documented. This portion was initially available in README.Debian
      file, but moved into here.
    </para>
    <sect1>
      <title>pbuilder create fails</title>
      <para>
	It often happens that pbuilder cannot create latest chroot.
	Try upgrading pbuilder and debootstrap.
	It is currently only possible to create software that handles the 
	past. Future prediction is a feature which may be added later after 
	we have become comfortable with the past. 
      </para>
      <para>
	There are people who occasionally backport debootstrap to stable
	versions, hunt for them.
      </para>
      <para>
	When there are errors with debootstrap phase, debootstrap script needs to be 
	fixed.
	pbuilder does not provide a way to work around debootstrap.
      </para>
    </sect1>
    <sect1>
      <title>Notes on usage of $TMPDIR</title>
      <para>
	If you are setting $TMPDIR to an unusual value, of other than
	<filename>/tmp</filename>, you will find that some errors may occur inside the chroot,
	such as <command>dpkg-source</command> failing.
      </para>
      <para>There are two options, you may install a hook to create that
	directory, or set 
	<screen>export TMPDIR=/tmp</screen>
	in pbuilderrc. Take your pick.
      </para>
    </sect1>
    <sect1>
      <title>Using special apt sources list other than the default</title>
      <para>
	If you have some very specialized requirements on your 
	apt setup inside pbuilder, 
	it is possible to specify that through 
	<command><option>--othermirror</option></command>
	option.
	Try something like:
	<command><option>--othermirror "deb http://local/mirror stable main|deb-src http://local/source/repository ./"</option></command>
      </para>
      <para>
	To use the local filesystem instead of http, it is necessary to do 
	bind-mounting.
	<command><option>--bindmounts</option></command>
	is a command-line option useful for such cases.
      </para>
    </sect1>
    <sect1>
      <title>How to get pbuilder to run apt-get update before trying to satisfy build-dependency</title>
      <para>
	You can use hook scripts for this.
	D scripts are run before satisfying build-dependency.
      </para>
    </sect1>
    <sect1>
      <title>Different bash prompts inside pbuilder login</title>
      <para>
	To make distinguishing bash prompts inside pbuilder
	easier, it is possible to set environmental variables such as PS1
	inside <filename>pbuilderrc</filename>
      </para>
      <screen>
	export PS1="pbuild chroot 32165 # "
      </screen>
    </sect1>
    <sect1>
      <title>Using /var/cache/apt/archives for package cache</title>
      <para>
	For the help of low-bandwidth systems,
	it is possible to use <filename>/var/cache/apt/archives</filename> as the 
	package cache.
	Just specify it instead of the default <filename>/var/cache/pbuilder/aptcache</filename>.
      </para>
      <para>
	It is however not possible to do so currently with user-mode-linux 
	version of pbuilder, because <filename>/var/cache/apt/archives</filename>
	is usually only writable as root.
      </para>
      <para>
	Use of dedicated tools such as apt-proxy is recommended, since caching of packages 
	would benefit the system outside the scope of pbuilder.
      </para>
    </sect1>
    <sect1 id="woodybackport">
      <title>pbuilder backported to stable Debian releases</title>
      <para>
	It is known that Brian May does a backport of 
	pbuilder, available at:
	<screen>deb http://www.microcomaustralia.com.au/debian/ woody main</screen>
      </para>
    </sect1>
    <sect1 id="LOGNAME">
      <title>Warning on LOGNAME not being defined</title>
      <para>
	You might see a lot of warning messages when running pbuilder.
      </para>
      <para>
	<screen>
	dpkg-genchanges: warning: no utmp entry available and LOGNAME not defined; using uid of process (1234)
	</screen>
      </para>
      <para>
	It is currently safe to ignore this warning message.
	Please report back if you find any problem with having LOGNAME unset.
	Setting LOGNAME caused a few problems when invoking chroot.
      </para>
    </sect1>
    <sect1 id="nobuildconflictessential">
      <title>Cannot Build-conflict against an essential package</title>
      <para>
	pbuilder does not currently allow Build-Conflicts against 
	essential packages.
	It should be obvious that essential packages should not be 
	removed from a working Debian system, and a source 
	package should not try to force removal of such packages 
	to people building the package.
      </para>
    </sect1>
    <sect1>
      <title>Avoiding the "ln: Invalid cross-device link" message</title>
      <para>
	By default, pbuilder uses hard links to manage pbuilder package cache.
	It is not possible to make hard links across different devices; 
	and thus this error will occur, depending on your set up.
	If this happens, set <screen>APTCACHEHARDLINK=no</screen>
	in your pbuilderrc file.
      </para>
    </sect1>
    <sect1>
      <title>Using fakechroot</title>
      <para>
	It is possible to use <command>fakechroot</command> instead of being root
	to run pbuilder; however, several things make this impractical.
	<command>fakechroot</command> overrides library loads and tries to 
	override default libc functions when providing the functionality of
	virtual chroot.
	However, some binaries do no use libc to function, or override the overriding 
	provided by fakechroot. 
	One example is <command>ldd</command>.
	<command>ldd</command> outout inside <command>fakechroot</command>
	will check the library dependency outside of chroot; which is not the 
	expected behavior.
      </para>
      <para>
	To work around the problem fakechroot provides a patch for debootstrap.
	Use that, so that ldd and ldconfig are overridden.
      </para>
      <para>
	Make sure you have set your path correctly, as described in <filename>/usr/share/doc/fakechroot/README.Debian</filename>
      </para>
    </sect1>
    <sect1 id="debconfinsidepbuilder">
      <title>Using debconf inside pbuilder sessions</title>
      <para>
	To use debconf inside pbuilder, setting DEBIAN_FRONTEND to 
	<quote>readline</quote> in <filename>pbuilderrc</filename> should work.
	Setting it to <quote>dialog</quote> should also work, but make sure
	whiptail or dialog is installed inside the chroot.
      </para>
    </sect1>
    <sect1 id="nodev">
      <title>nodev mount options hinder pbuilder activity</title>
      <para>
	If you see messages such as this in building chroot, you are mounting the filesystem with 
	nodev option.
      </para>
      <screen>
	/var/lib/dpkg/info/base-files.postinst: /dev/null: Permission denied
      </screen>
      <para>
	You will also have problems if you mount the filesystem with noexec option, or nosuid.
	Make sure you do not have these flags set when mounting the filesystem for 
	<filename>/var/cache/pbuilder</filename>; or $BUILDPLACE.
      </para>
      <para>
	This is not a problem on User-mode-linux.
      </para>
    </sect1>
    <sect1 id="faqslowpbuilder">
      <title>pbuilder is slow</title>
      <para>
	pbuilder is often slow. The slowest part of pbuilder is extracting of tar.gz every time 
	pbuilder is invoked. That can be avoided by using <command>pbuilder-user-mode-linux</command>.
	<command>pbuilder-user-mode-linux</command> uses 
	COW filesystem, and thus does not need to clean up and recreate the root filesystem.
      </para>
      <para>
	pbuilder-user-mode-linux is slower in executing the actual build system, due to the 
	usual user-mode-linux overhead for system calls. It is more friendly to the hard drive.
      </para>
    </sect1>
    <!-- end of FAQ -->
  </chapter>
  <chapter id="otheruse">
    <title>Other uses of pbuilder</title>
    <sect1 id="chroot">
      <title>Using pbuilder for small experiments</title>
      <para>
	There are cases when some small experimenting is required, and 
	do not want to damage the main system,
	like installing experimental library packages,
	or compiling with experimental compilers.
	For such cases, <command>pbuilder login</command> command is available.
      </para>
      <para>
	<command>pbuilder login </command> is a debugging feature for 
	pbuilder itself, but it also allows users to have a temporal chroot.
      </para>
      <para>
	Note that chroot is cleaned after logging out of the shell,
	and mounting file systems inside it is considered harmful.
      </para>
    </sect1>
    <sect1>
      <title>Running little programs inside the chroot</title>
      <para>
	To facilitate using pbuilder for other uses, 
	<command>pbuilder execute</command> is available.
	<command>pbuilder execute </command> will take a script 
	specified in the command-line argument, and 
	invoke the script inside the chroot.
      </para>
      <para>
	The script can be useful for sequence of operations such as
	installing ssh and adding a new user inside the chroot.
      </para>
    </sect1>
  </chapter>
  <chapter id="experimental">
    <title>Experimental or wish list features of pbuilder</title>
    <para>
      There are some advanced features, above that of the 
      basic feature of pbuilder, for some specific purposes.
    </para>
    <sect1 id="lvm">
      <title>Using LVM</title>
      <para>
	LVM has snapshot function that features Copy-on-write images.
	That could be used for pbuilder just it can be used for 
	user-mode-linux pbuilder port.
	It may prove to be faster, but it is not implemented yet,
	and so no measurement has been made, yet.
      </para>
      <para>
	Since user-mode-linux port seems to be more interesting,
	this is abandoned.
      </para>
    </sect1>
    <sect1 id="withouttargz">
      <title>Using pbuilder without tar.gz</title>
      <para>
	<command><option>--no-targz</option></command>
	option of <command>pbuilder</command>
	will allow usage of pbuilder in a different way
	to conventional usage.
	It will try to use existing chroot, 
	and will not try to clean up after 
	working on it.
	It is an operation mode more like 
	<command>sbuild</command>.
      </para>
      <para>
	It should be possible to create chroot images
	for <command>dchroot</command> with following commands:
	<screen>
# pbuilder create --distribution potato --no-targz --basetgz /chroot/potato
# pbuilder create --distribution woody --no-targz --basetgz /chroot/woody
# pbuilder create --distribution sid --no-targz --basetgz /chroot/sid
	</screen>
      </para>
    </sect1>
  </chapter>
  <chapter>
    <title>Minor details</title>
    <sect1>
      <title>Documentation history </title>
      <para>
	This document is started on 28 Dec 2002 by
	Junichi Uekawa, trying to document what is known
	about pbuilder.
      </para>
      <para>
	This documentation is available from pbuilder source tarball,
	and from CVS repository of pbuilder (a web-based acces is possible).
	A copy of this documentation can be found in
	<ulink url="http://www.netfort.gr.jp/~dancer/software/pbuilder-doc/pbuilder-doc.html">Netfort page for pbuilder</ulink>.
	The homepage for pbuilder is 
	<ulink url="http://www.netfort.gr.jp/~dancer/software/pbuilder.html">
	  http://www.netfort.gr.jp/~dancer/software/pbuilder.html
	</ulink>
      </para>
    </sect1>
    <sect1 id="pbuilderbackgroundhistory">
      <title>Possibly inaccurate Background History of pbuilder</title>
      <para>
	The following is most possibly inaccurate account of how 
	pbuilder happened to come, and other attempts to 
	make something like pbuilder to happen.
	This part of document was originally in AUTHORS file,
	to give credit to those who existed before pbuilder.
      </para>
      <sect2>
	<title>The Time Before pbuilder</title>
	<para>
	  There were dbuild, which was a shell script to build
	  Debian packages from source. Lars Wirzenius wrote that 
	  script, and it was good, short, and simple (probably).
	  There was nothing like build-depends then (I think), and it was simple.
	  It could have been improved, I could only find references and no actual source.
	</para>
	<para>
	  debbuild was probably written by James Troup. I don't know it 
	  because I have never seen the actual code, I could only find some
	  references to it on the net, and mailing list logs.
	</para>
	<para>
	  sbuild is a perl script to build Debian package from source.
	  It parses Build-Dependency, and performs other misc checks,
	  and has a lot of hacks to actually get things building,
	  including a table of what package to use when virtual packages are
	  specified (does it do that still?).
	  It supports use of local database for packages which do not 
	  have build-dependency. It was written by Ronan Hodek, 
	  and I think it was patched and fixed and extended by
	  several people. It is part of wanna-build, and used extensively
	  in Debian buildd system. I think it was maintained
	  mostly by Ryan Murray.
	</para>
      </sect2>
      <sect2>
	<title>Birth of pbuilder</title>
	<para>
	  wanna-build (sbuild) was quite difficult to set up, and it was 
	  never a Debian package. dbuild was something that predated
	  Build-Depends.
	</para>
	<para>
	  Building package from source using Build-Depends 
	  information within a chroot sounded trivial; and 
	  pbuilder was born. It was initially a shell script
	  with only a few lines, which called debootstrap
	  and chroot and dpkg-buildpackage in the same run,
	  but soon, it was decided that's too slow.
	</para>
	<para>
	  Yes, and it took almost an year to get things somewhat 
	  right, and in the middle of the process, Debian 3.0
	  was released. Yay.
	  Debian 3.0 wasn't completely buildable with pbuilder,
	  but the amount of packages which are not buildable
	  are steadily decreasing. (I hope)
	</para>
      </sect2>
      <sect2>
	<title>And the second year of its life</title>
	<para>
	  And someone wanted pbuilder to run as not root,
	  and User-mode-linux has become more useful as time passed,
	  I've started experimenting with pbuilder-uml.
	  pbuilder-uml has not been able to run as often as it should,
	  and bootstrapping user-mode-linux environment has been
	  pretty hard.
	</para>
	<para>
	  The third year is already there. pbuilder is widely adopted, and activity is focused on fixing minor problems.
	  Some features are added, but most was filling the missing portions for user-mode-linux port.
	</para>
      </sect2>
    </sect1>
  </chapter>
</book>