Changes & Errata

Faulty way of spawning sshd in single-user mode (page 299)

madduck — 2006-10-22T15:25:26Z

In chapter 6.3.1, I suggest to add sshd to the /etc/inittab file to be able to login to a remote system even in single-user mode:

# sed -i -e "/^~~/ish:S:respawn:sshd -Do 'AllowUsers=root'" /etc/inittab

Unfortunately, there are two errors with this: first, sshd must be called with the complete path (to guard against trojans), and init must be told to reload the configuration file after the change.

The following corrects both problems:

# sed -i -e "/^~~/ish:S:respawn:/usr/sbin/sshd -Do 'AllowUsers=root'" /etc/inittab
# telinit q

Default-Release setting in wrong namespace (page 169)

madduck — 2006-07-30T15:17:55Z

The apt.conf examples on page 169, which illustrate the two different syntax styles, list Default-Release under the wrong namespace. Instead of APT::Get, it should just be APT:

APT::Default-Release "sarge";
[...]

and:

APT {
  [...]
  Default-Release "sarge";
  [...]
}

Wrong argument to apt-cdrom (page 167)

madduck — 2006-07-30T15:17:59Z

The argument to apt-cdrom should be add, not --cdrom. Therefore, the first example on page 167 in section should read:

# apt-cdrom add /media/cdrom
Using CD-ROM mount point /media/cdrom/
[...]

Deborphan may need to be run iteratively (page 248)

madduck — 2006-07-30T14:06:57Z

Deborphaner is not iterative (or recursive, depending on how you look at it). In one run it may suggest to remove a set of packages, but it fails to identify packages that would be obsolete if the user removed the packages suggested in the first run.

MIRROR variable incomplete (page 408)

madduck — 2006-07-30T13:46:02Z

In section 8.3.1, the $MIRROR variable set in the example is incomplete: it lacks the path to the /debian directory. The assignment should read:

# MIRROR=http://ftp.debian.org/debian

Regardless, you should still use apt-spy to determine a closer mirror!

Removed state is called deinstall, not remove (page 152)

madduck — 2006-06-25T10:03:17Z

The name of the state of a package that has been removed is called deinstall, not remove.

Missing argument to cut command (page 148)

madduck — 2006-07-30T15:09:36Z

At the bottom of the page, the cut command is missing the field delimiter argument. The correct line reads:

dpkg-query --show --showformat='${Status} ${Package}\n' \
  | grep ^deinstall | cut -f4 -d' ' | xargs dpkg -P

amd64 architecture added to official archive (page 116)

madduck — 2006-03-16T09:24:19Z

The integration of the amd64 architecture into the official archive is underway as part of the mirror split, and the first package has been uploaded. Within the next few weeks, amd64 will thus become an official Debian architecture, and it shall be released as part of Debian etch, the next stable release.

Missing folder level in figure (page 105)

madduck — 2006-02-16T10:06:36Z

Unfortunately, Figure 4.1 in section 4.1 is missing a level of folders. Below /debian/dists/sarge, each section (main, contrib, non-free) gets a folder, which then hold the binary-* and source folders each.

The corrected diagram looks like this (click to enlarge):

Bad versioning scheme for pre-release versions (page 218)

madduck — 2006-02-01T11:51:44Z

The versioning scheme for pre-release upstream versions proposed in section 5.7.5 is not desirable: encoding the pre-release version in the Debian revision prevents a new orig.tar.gz file from being uploaded when the final release is uploaded.

The following rewrite should make the situation clear. It replaces the second half of the middle paragraphon page 218, starting at "Within the Debian archive, it is customary...":

One scheme could be to release 1.0-rc1 as 1.0-0+1.0rc1+1, followed by 1.0-0+1.0rc1+2, and then 1.0-1 when the final gets released. However, this approach has an inherent problem: for each upstream version, an orig.tar.gz file exists in the Debian archive; Debian revisions are released as diff.gz files against the orig.tar.gz file (see chapter 9.2.12). In the proposed scheme, the orig.tar.gz file will contain the 1.0-rc1 upstream release, and when the final 1.0 release is to be packaged, the diff.gz file for the 1.0-1 Debian release will have to encompass all upstream changes between 1.0-rc1 and 1.0 as well, which is undesirable.

Thus, a better approach is to encode the pre-release version as part of the upstream vesion. This can be done in one of two ways: using the previous upstream version as base (let's assume 0.90), or an obviously fake upstream version that sorts before the final release: 0.90+1.0rc1-1 or 0.999+1.0rc1-1. Now, upon release of 1.0, a new orig.tar.gz file can be uploaded to replace the previous one. With that in mind, it should be easy to infer the upstream version number from the Debian version, even in complex cases.

Standard mode allows to choose from a set of tags (page 540)

madduck — 2006-01-31T14:53:16Z

The item on reportbug's standard mode mentions a set of patches to be applied to the bug report. Instead of patches, this should read tags.

Two small errors in preinst file (page 490)

madduck — 2006-01-30T22:34:11Z

The listing in section 9.4.1 contains two small errors related to the preinst file:

The cat instruction should be redirected to debian/foo.preinst, not debian/foo/preinst.
The version comparison within the preinst file should compare against 1.2.3-4, because presumably only versions before 1.2.3-4 used a working directory in /var/state.

Unclear wording on Pre-Depends relation (page 210)

madduck — 2006-01-30T10:11:34Z

The description of the Pre-Depends relation as part of the discussion of the Depends relation in section 5.7.3 is unclear. A better explanation is:

Another relation, Pre-Depends, provides a tighter dependency and is only used in very special cases;
packages listed here need to be fully configured before the dependending package can be unpacked or configured. If a previous version of the pre-dependent package has once been configured on the system, the depending package can be unpacked (but not configured) even if the current version of the pre-dependent package has not been configured yet.

Components select non-free software, not non-US (page 166)

madduck — 2006-01-26T15:08:05Z

The item on components on the top of page 166 states that components "also specify when non-US software is to be used."

This should say "non-free software" instead. Components cannot be used to select non-US software.

Wrong APT source line for non-US archive (page 164)

madduck — 2006-01-26T15:05:28Z

In the first listing in section 5.4.1, the line for the non-US archive should be:

deb http://nonus.debian.org/debian-non-US sarge/non-US main

This is to say: the name non-US is also part of the distribution.

grub-update should be update-grub (page 413)

madduck — 2006-01-26T11:47:32Z

The (Debian) command to update grub's menu.lst file is update-grub, not grub-update, which erroneously appears several times on pages 413ff.

Debian still fastest growing distro (page 18)

madduck — 2006-01-10T22:42:18Z

Netcraft has determined Debian again to be the fastest growing Linux distribution (on web servers) in 2005.

Wrong hostname for the Debian snapshot server (page 266)

madduck — 2006-01-10T14:27:36Z

The third paragraph of section 5.12.3 refers to snapshot.debian.org. The correct hostname is snapshot.debian.net.

Wrong port and confusing assumption (page 250)

madduck — 2006-01-09T19:57:42Z

In the subsection on apt-proxy of section 5.11.7, the sources.list file does not include apt-proxy's default port 9999. Instead, it should read:

~# cat <<EOF > /etc/apt/sources.list
http://arakis:9999/debian sarge main
http://arakis:9999/security sarge/updates main
http://arakis:9999/pdo/~madduck/packages/stage ./

In addition, the paragraph just before the snippet says that the machine running apt-proxy must be resolvable from the machine named arakis. Rather, the machine running apt-proxy must be resolvable as arakis from the machine hosting the sources.list file.

New Wiki page detailing Secure APT (page 373)

madduck — 2006-01-07T10:53:20Z

Joey Hess added a page to the Debian Wiki with the goal to better document APT 0.6, aka. Secure APT. This should augment the information you can find in section 7.5.2.

Debian Linux Kernel Handbook released (page 382)

madduck — 2006-01-06T19:04:39Z

Jurij Smakov et al. have published the Debian Linux Kernel Handbook, which documentswill help in documenting the internals of the Debian Linux Kernel build process. The document is still work in progress.

Even though the kernel team does not use kernel-package, the document surely contains a great amount of useful or interesting information.

New ftpmaster key for 2006 (page 574)

madduck — 2006-01-04T12:39:24Z

On 3 January 2006, a new archive signing key for the main Debian archive was put in place. The following are the relevant data to help you verify it.

        URL: http://ftp-master.debian.org/ziyi_key_2006.asc
         ID: 2d230c5f
       Date: 2003-01-03
Fingerprint: 0847 50fc 01a6 d388 a643 d869 0109 0831 2d23 0c5f
    Creator: Anthony Towns (key 0x2a4e3eaa)

As in the book, this information comes without any warranty.

Free software is not a subset of Open Source (page 40)

madduck — 2005-12-13T17:33:07Z

In chapter 2.2.2, Free Software is incorrectly described as a subset of Open Source: while it is true that there are there Open Source licenses which are not FSF-Free or not approved by Debian, that is a matter of interpretation, not of principles, as the Open Source Definition and the Debian Free Software Guidelines match almost word for word.

Qmail is not Open Source (page 40)

madduck — 2005-12-13T17:35:22Z

In the end of section 2.2.2, I cite Qmail as an example of non-free open source software. Here, I have made the common mistake of equating availability of source with "open-source-ness". Qmail is non-free, and not Open Source by the Open Source Definition, although its sources are available.

QPL situation not correctly described (page 33)

madduck — 2005-12-13T16:01:10Z

In subsection "Into the next milennium" in section 2.1, I state that Trolltech, the manufacturer of the Qt library, "agreed to license the library under the GNU Public License (GPL) for non-commercial use."

Instead, it should read: "[Trolltech] agreed to license they X11/*nix library under the GNU Public License (GPL) thus making it compatible with the Debian Free Software Guidelines."