m19u3l / lfs-pacman

Guide to using pacman as a package manager for Linux From Scratch

Pacman on LFS 8.1

Based on the guide writen by James Kimball in 2013.
Licensed under the Creative Commons Attribution-ShareAlike 3.0 License.

Introduction

This guide is divided in five stages, the first one of which starts just before installing tools to your final system.

• Stage 1 - Installing pacman to your temporary toolchain
• Stage 2 - Installing pacman with pacman
• Stage 3 - Installing packages of chapter six of the LFS book
• Stage 4 - Installing pacman to your final system
• Stage 5 - Finishing the book

Stage 1 - Installing pacman to your temporary toolchain

This stage begins right before section 6.7. Linux-4.9.9 API Headers of the LFS 8.1 book.

Pacman dependencies

Pacman depends on the following packages:

• zlib
• libarchive
• pkg-config
• fakeroot, which in turn depends on libcap

Most of these are not part of the LFS book, so download their sources manually:

• libarchive: https://www.libarchive.org/downloads/libarchive-3.3.2.tar.gz
• fakeroot: http://turul.canonical.com/pool/main/f/fakeroot/fakeroot_1.22.orig.tar.bz2
• pacman: https://sources.archlinux.org/other/pacman/pacman-5.0.2.tar.gz

Build these packages using the following commands. Just like the LFS book, these commands assume you've extracted the relevant sources and cd'd into the resulting directory.

zlib 1.2.11

./configure --prefix=/tools
make
make install

libarchive 3.3.2

./configure --prefix=/tools --without-xml2 --disable-shared
make
make install

pkg-config 0.29.2

./configure --prefix=/tools            \
            --with-internal-glib       \
            --disable-compile-warnings \
            --disable-host-tool        \
            --disable-shared           \
            --docdir=/tools/share/doc/pkg-config-0.29.2
make
make install

libcap 2.25

make
make RAISE_SETFCAP=no lib=lib prefix=/tools install
chmod -v 755 /tools/lib/libcap.so

fakeroot 1.22

./configure --prefix=/tools                 \
            --libdir=/tools/lib/libfakeroot \
            --with-ipc=sysv
make
make install

Pacman 5.0.2

./configure --prefix=/tools   \
            --disable-doc     \
            --disable-shared  \
            --sysconfdir=/etc \
            --localstatedir=/var
make
make install

This will have installed, amongst others, the makepkg.conf and pacman.conf config files in /etc; you may want to edit them. For makepkg.conf, be sure that CARCH and CHOST are appropriate, e.g.:

CARCH="x86_64"
CHOST="x86_64-pc-linux-gnu"

You can set your name and email address as the PACKAGER if you want.

Setting up to build packages with pacman

Create a new user by adding the following to /etc/passwd:

ben:x:1000:999:Ben:/home/ben:/bin/bash

Where 999 is the ID of the users group. Check /etc/group for the correct ID, or if users is not present in that file, add the following to it.

users:x:999:

Create a home directory:

mkdir -v /home/ben
chown -Rv ben:users /home/ben

Exit your current chroot, then chroot into your new user (make sure 1000, 999 and ben are set to the proper values for your system):

chroot --userspec=1000:999 "$LFS" /tools/bin/env -i \
     HOME=/home/ben     \
     TERM="$TERM"       \
     PS1='$? \u:\w \$ ' \
     PATH=/bin:/usr/bin:/sbin:/usr/sbin:/tools/bin:/tools/sbin \
     /tools/bin/bash --login +h

You may want to create a builds directory in your home dir. In there, you would then create a directory for each package you're building.

Stage 2 - Installing pacman with pacman

Copy the pacman sources to its build directory, ~/builds/pacman-5.0.2.

Download the necessary build files (PKGBUILD, makepkg.conf and pacman.conf.x86_64) from the Arch Linux packages repo to the build directory.

Edit the PKGBUILD file:

• Comment out the groups and depends lines. We're not using package groups, and as far as pacman knows none of the dependencies are installed.
• Edit the source variable so that only the pacman source tarball (not the URL) and the three downloaded files are present.

Change the configure call in the build function to:

./configure              
    --prefix=/tools      \
    --sysconfdir=/etc    \
    --localstatedir=/var \
    --disable-doc        \
    --disable-shared

Comment out the check function; the tests won't run without Python.

Now run the following command as your non-root user from the build directory:

makepkg --skipchecksums

We're skipping the checksums because we don't have OpenSSL installed yet.

If all goes well, this should have created a file that you can now install as follows, as root this time:

pacman -U pacman-5.0.2-2-x86_64.pkg.tar.gz

Stage 3 - Installing packages of chapter six of the LFS book

Now we will continue with the rest of the book, but instead of building and installing the packages manually, we will create packages and then use pacman to install them.

All of the necessary PKGBUILD files can be found in the packages directory, but if you want to learn how to create these, I suggest you only refer to them when you get stuck.

Creating a package

The general process goes like this:

1. Create a new directory in the builds directory.
2. Copy all needed files to it (source archive, possibly other files like patches or config files).
3. Write a PKGBUILD file.
4. Run makepkg --skipchecksums.
5. Check the contents of the pkg directory; this is what pacman will install, so you may want to verify that it looks good.
6. Install the package (as root) with pacman -U $filename

Writing a PKGBUILD file can take some trial and error. Essentially you'll need to copy what the LFS book wants you to do and paste it in the PKGBUILD at the right place, but usually you will not be able to copy things verbatim from the book.

If you're stuck, check the official Arch Linux packages or thePKGBUILD files in the packages directory of this repo.

Tips

Source directory

When calling any of the PKGBUILD functions, makepkg will automatically cd you into the source dir, which is where it will have extracted or symlinked all your source files.

Source tarball

makepkg will automatically extract all archives you specify in the sources array. Typically, your source tarball will have been extracted into a separate directory (although that depends on the tarball itself; the tzdata tarball for instance, extracts directly, without a subdirectory).

This is why the first step of each function will usually be to cd into the directory created during the extraction of the source tarball.

Installing files

When installing files, you cannot install them to the system root, but instead you have to install them in ${pkgdir}. For certain packages this is done by using make DESTDIR=${pkgdir} install instead of mkae install. Not all packages use DESTDIR, however. If you're not sure how those packages should be built, you can always check the Arch Linux packages or the PKGBUILD files from this repo.

In some cases, the book will tell you to mv a directory. This will work while creating the package, but will cause problems when installing it. You should first create the directory with install -vdm755 $dir_name.

Post-install

Things that the LFS book wants you to do after having called make install will likely need to be placed in an .install file. Check the Arch Linux wiki for more info.

Pacman will execute the functions in the .install file at the end of the installation process.

Notes for individual packages

Some packages require additional steps besides simply converting the LFS instructions into a PKGBUILD. These steps are documented here.

6.9. Glibc-2.26

The book wants you to create some symlinks; I did that manually, as I felt it would be out of place in the package.

The tzdata part of glibc requires zic to be installed to the system, which means after glibc was installed with pacman -U. While I suppose you could directly call the zic binary residing in the src or pkg directories, I thought it would be cleaner to split the tzdata installation to a separate package, much like Arch Linux does.

6.10. Adjusting the Toolchain

I did these steps manually. It didn't feel suitable to (ab)use makepkg/pacman for this purpose.

6.15. Bc-1.07.1

The book wants you to create symlinks for libncurses. I did this manually before building the package.

6.20. GCC-7.2.0

Before building the package, increase the stack size: ulimit -s 32768.

I had to use --force when installing this package, since some libraries already existed on the system.

6.28. Shadow-4.5

I ran passwd manually.

6.34. Bash-4.4

When creating the package, makepkg told me that "Package contains reference to $srcdir". Using grep -R "$(pwd)/src" pkg/, I found out that Bash installs Makefile.inc to /usr/lib/bash/, which contains a reference to the build directory. On an existing Arch Linux installation, /usr/lib/bash/Makefile.inc also contained a reference to a (non-existing) build directory, so I assume this is benign.

Use --force to install this package, since /bin/bash was created as part of 6.6. Creating Essential Files and Symlinks.

I then re-chrooted, using /bin/bash instead of /tools/bin/bash.

6.40. Perl-5.26.0

The LFS book tells you to create /etc/hosts. I've chosen to do this manually, rather than to have the Perl package install this file. It doesn't sound right that Perl should own this file. For reference, in Arch Linux, the hosts file is owned by the filesystem package, which contains the base Arch Linux files, so it makes sense that this is created manually in the case of LFS.

Use --force to install this package, since /usr/bin/perl was created as part of 6.6. Creating Essential Files and Symlinks.

6.50. Coreutils-8.27

For some reason, doing the in place sed (sed -i) on chroot.8 resulted in the file having 000 permissions. I replaced it with a regular sed, redirecting the result to a new file, then using install to copy the file to its destination.

Use --force to install this package, since a number of files already exist (amongst others cat, dd, echo) in /bin (as symlinks to /tools). These were added in 6.6. Creating Essential Files and Symlinks.

6.53. Findutils-4.6.0

As with coreutils, using in place sed set the permissions to 000, so I used the same workaround here.

6.63. Sysklogd-1.5.1

Sysklogd's makefile doesn't support specifying a destination directory when installing (make DESTDIR=/path). I've included a patch that adds this.

Stage 4 - Installing pacman to your final system

Stage four starts immediately after the last package in chapter six, currently vim. Before continuing with the rest of the chapter, build and install pacman and its dependencies.

As part of chapter six you should already have installed most of these packages, except for:

• libarchive
• fakeroot
• pacman

Use your temporary pacman installation to install them. Remember, we're installing to the final system, not to /tools.

Stage 5 - Finishing the book

Finish up the rest of the book manually.

When restarting my machine, the LFS system wouldn't boot properly. It turned out that many binaries and other files were owned by ben, the user with which I built the packages. I have no idea why that happened, but chowning them to root:root allowed my system to boot.