The XBPS source packages collection

This repository contains the XBPS source packages collection to build binary packages for the Void Linux distribution.

The included xbps-src script will fetch and compile the sources, and install its files into a fake destdir to generate XBPS binary packages that can be installed or queried through the xbps-install(1) and xbps-query(1) utilities, respectively.

See Contributing for a general overview of how to contribute and the Manual for details of how to create source packages.

Table of Contents

• Requirements
• Quick start
• chroot methods
• Install the bootstrap packages
• Configuration
• Directory hierarchy
• Building packages
• Package build options
• Sharing and signing your local repositories
• Rebuilding and overwriting existing local packages
• Enabling distcc for distributed compilation
• Distfiles mirrors
• Cross compiling packages for a target architecture
• Using xbps-src in a foreign Linux distribution
• Remaking the masterdir
• Keeping your masterdir uptodate
• Building 32bit packages on x86_64
• Building packages natively for the musl C library
• Building void base-system from scratch

Requirements

• GNU bash
• xbps >= 0.56
• git(1) - unless configured to not, see etc/defaults.conf
• common POSIX utilities included by default in almost all UNIX systems
• curl(1) - required by xbps-src update-check

For bootstrapping additionally:

• flock(1) - util-linux
• bsdtar or GNU tar (in that order of preference)
• install(1) - GNU coreutils
• objcopy(1), objdump(1), strip(1): binutils

xbps-src requires a utility to chroot and bind mount existing directories into a masterdir that is used as its main chroot directory. xbps-src supports multiple utilities to accomplish this task:

• bwrap - bubblewrap, see https://github.com/projectatomic/bubblewrap.
• ethereal - only useful for one-shot containers, i.e docker (used with CI).
• xbps-uunshare(1) - XBPS utility that uses user_namespaces(7) (part of xbps, default).
• xbps-uchroot(1) - XBPS utility that uses namespaces and must be setgid (part of xbps).

NOTE: xbps-src does not allow building as root anymore. Use one of the chroot methods shown above.

Quick start

Clone the void-packages git repository and install the bootstrap packages:

$ git clone git://github.com/void-linux/void-packages.git
$ cd void-packages
$ ./xbps-src binary-bootstrap

Build a package by specifying the pkg target and the package name:

$ ./xbps-src pkg <package_name>

Use ./xbps-src -h to list all available targets and options.

To build packages marked as 'restricted', modify etc/conf:

$ echo XBPS_ALLOW_RESTRICTED=yes >> etc/conf

Once built, the package will be available in hostdir/binpkgs or an appropriate subdirectory (e.g. hostdir/binpkgs/nonfree). To install the package:

# xbps-install --repository hostdir/binpkgs <package_name>

Alternatively, packages can be installed with the xi utility, from the xtools package. xi takes the repository of the current working directory into account.

# xi <package_name>

chroot methods

xbps-uunshare(1) (default)

This utility requires these Linux kernel options:

• CONFIG_NAMESPACES
• CONFIG_IPC_NS
• CONFIG_UTS_NS
• CONFIG_USER_NS

This is the default method, and if your system does not support any of the required kernel options it will fail with EINVAL (Invalid argument).

xbps-uchroot(1)

This utility requires these Linux kernel options:

• CONFIG_NAMESPACES
• CONFIG_IPC_NS
• CONFIG_PID_NS
• CONFIG_UTS_NS

Your user must be added to a special group to be able to use xbps-uchroot(1) and the executable must be setgid:

# chown root:<group> xbps-uchroot
# chmod 4750 xbps-uchroot
# usermod -a -G <group> <user>

NOTE: by default in void you shouldn't do this manually, your user must be a member of the xbuilder group.

To enable it:

$ cd void-packages
$ echo XBPS_CHROOT_CMD=uchroot >> etc/conf

If for some reason it's erroring out as ERROR clone (Operation not permitted), check that your user is a member of the required group and that xbps-uchroot(1) utility has the proper permissions and owner/group as explained above.

Install the bootstrap packages

There is a set of packages that makes up the initial build container, called the bootstrap. These packages are installed into the masterdir in order to create the container.

The primary and recommended way to set up this container is using the binary-bootstrap command. This will use pre-existing binary packages, either from remote xbps repositories or from your local repository.

There is also the bootstrap command, which will build all necessary bootstrap packages from scratch. This is usually not recommended, since those packages are built using your host system's toolchain and are neither fully featured nor reproducible (your host system may influence the build) and thus should only be used as a stage 0 for bootstrapping new Void systems.

If you still choose to use bootstrap, use the resulting stage 0 container to rebuild all bootstrap packages again, then use binary-bootstrap (stage 1) and rebuild the bootstrap packages once more (to gain stage 2, and then use binary-bootstrap again). Once you've done that, you will have a bootstrap set equivalent to using binary-bootstrap in the first place.

Also keep in mind that a full source bootstrap is time consuming and will require having an assortment of utilities installed in your host system, such as binutils, gcc, perl, texinfo and others.

Configuration

The etc/defaults.conf file contains the possible settings that can be overridden through the etc/conf configuration file for the xbps-src utility; if that file does not exist, will try to read configuration settings from $XDG_CONFIG_HOME/xbps-src.conf, ~/.config/xbps-src.conf, ~/.xbps-src.conf.

If you want to customize default CFLAGS, CXXFLAGS and LDFLAGS, don't override those defined in etc/defaults.conf, set them on etc/conf instead i.e:

$ echo 'XBPS_CFLAGS="your flags here"' >> etc/conf
$ echo 'XBPS_LDFLAGS="your flags here"' >> etc/conf

Native and cross compiler/linker flags are set per architecture in common/build-profiles and common/cross-profiles respectively. Ideally those settings are good enough by default, and there's no need to set your own unless you know what you are doing.

Virtual packages

The etc/defaults.virtual file contains the default replacements for virtual packages, used as dependencies in the source packages tree.

If you want to customize those replacements, copy etc/defaults.virtual to etc/virtual and edit it accordingly to your needs.

Directory hierarchy

The following directory hierarchy is used with a default configuration file:

     /void-packages
        |- common
        |- etc
        |- srcpkgs
        |  |- xbps
        |     |- template
        |
        |- hostdir
        |  |- binpkgs ...
        |  |- ccache ...
        |  |- distcc-<arch> ...
        |  |- repocache ...
        |  |- sources ...
        |
        |- masterdir
        |  |- builddir -> ...
        |  |- destdir -> ...
        |  |- host -> bind mounted from <hostdir>
        |  |- void-packages -> bind mounted from <void-packages>

The description of these directories is as follows:

• masterdir: master directory to be used as rootfs to build/install packages.
• builddir: to unpack package source tarballs and where packages are built.
• destdir: to install packages, aka fake destdir.
• hostdir/ccache: to store ccache data if the XBPS_CCACHE option is enabled.
• hostdir/distcc-<arch>: to store distcc data if the XBPS_DISTCC option is enabled.
• hostdir/repocache: to store binary packages from remote repositories.
• hostdir/sources: to store package sources.
• hostdir/binpkgs: local repository to store generated binary packages.

Building packages

The simplest form of building package is accomplished by running the pkg target in xbps-src:

$ cd void-packages
$ ./xbps-src pkg <pkgname>

When the package and its required dependencies are built, the binary packages will be created and registered in the default local repository at hostdir/binpkgs; the path to this local repository can be added to any xbps configuration file (see xbps.d(5)) or by explicitly appending them via cmdline, i.e:

$ xbps-install --repository=hostdir/binpkgs ...
$ xbps-query --repository=hostdir/binpkgs ...

By default xbps-src will try to resolve package dependencies in this order:

• If a dependency exists in the local repository, use it (hostdir/binpkgs).
• If a dependency exists in a remote repository, use it.
• If a dependency exists in a source package, use it.

It is possible to avoid using remote repositories completely by using the -N flag.

The default local repository may contain multiple sub-repositories: debug, multilib, etc.

Package build options

The supported build options for a source package can be shown with xbps-src show-options:

$ ./xbps-src show-options foo

Build options can be enabled with the -o flag of xbps-src:

$ ./xbps-src -o option,option1 pkg foo

Build options can be disabled by prefixing them with ~:

$ ./xbps-src -o ~option,~option1 pkg foo

Both ways can be used together to enable and/or disable multiple options at the same time with xbps-src:

$ ./xbps-src -o option,~option1,~option2 pkg foo

The build options can also be shown for binary packages via xbps-query(1):

$ xbps-query -R --property=build-options foo

NOTE: if you build a package with a custom option, and that package is available in an official void repository, an update will ignore those options. Put that package on hold mode via xbps-pkgdb(1), i.e xbps-pkgdb -m hold foo to ignore updates with xbps-install -u. Once the package is on hold, the only way to update it is by declaring it explicitly: xbps-install -u foo.

Permanent global package build options can be set via XBPS_PKG_OPTIONS variable in the etc/conf configuration file. Per package build options can be set via XBPS_PKG_OPTIONS_<pkgname>.

NOTE: if pkgname contains dashes, those should be replaced by underscores i.e XBPS_PKG_OPTIONS_xorg_server=opt.

The list of supported package build options and its description is defined in the common/options.description file or in the template file.

Sharing and signing your local repositories

To share a local repository remotely it's mandatory to sign it and the binary packages stored on it. This is accomplished with the xbps-rindex(1) utility.

First a RSA key must be created with openssl(1) or ssh-keygen(1):

$ openssl genrsa -des3 -out privkey.pem 4096

or

$ ssh-keygen -t rsa -b 4096 -m PEM -f privkey.pem

Only RSA keys in PEM format are currently accepted by xbps.

Once the RSA private key is ready you can use it to initialize the repository metadata:

$ xbps-rindex --sign --signedby "I'm Groot" --privkey privkey.pem $PWD/hostdir/binpkgs

And then make a signature per package:

$ xbps-rindex --sign-pkg --privkey privkey.pem $PWD/hostdir/binpkgs/*.xbps

If --privkey is unset, it defaults to ~/.ssh/id_rsa.

If the RSA key was protected with a passphrase you'll have to type it, or alternatively set it via the XBPS_PASSPHRASE environment variable.

Once the binary packages have been signed, check the repository contains the appropriate hex fingerprint:

$ xbps-query --repository=hostdir/binpkgs -vL
...

Each time a binary package is created, a package signature must be created with --sign-pkg.

It is not possible to sign a repository with multiple RSA keys.

Rebuilding and overwriting existing local packages

If for whatever reason a package has been built and it is available in your local repository and you have to rebuild it without bumping its version or revision fields, it is possible to accomplish this task easily with xbps-src:

$ ./xbps-src -f pkg xbps

Reinstalling this package in your target rootdir can be easily done too:

$ xbps-install --repository=/path/to/local/repo -yff xbps-0.25_1

Please note that the package expression must be properly defined to explicitly pick up the package from the desired repository.

Enabling distcc for distributed compilation

Setup the slaves (machines that will compile the code):

# xbps-install -Sy distcc

Modify the configuration to allow your local network machines to use distcc (e.g. 192.168.2.0/24):

# echo "192.168.2.0/24" >> /etc/distcc/clients.allow

Enable and start the distccd service:

# ln -s /etc/sv/distccd /var/service

Install distcc on the host (machine that executes xbps-src) as well. Unless you want to use the host as slave from other machines, there is no need to modify the configuration.

On the host you can now enable distcc in the void-packages/etc/conf file:

XBPS_DISTCC=yes
XBPS_DISTCC_HOSTS="localhost/2 --localslots_cpp=24 192.168.2.101/9 192.168.2.102/2"
XBPS_MAKEJOBS=16

The example values assume a localhost CPU with 4 cores of which at most 2 are used for compiler jobs. The number of slots for preprocessor jobs is set to 24 in order to have enough preprocessed data for other CPUs to compile. The slave 192.168.2.101 has a CPU with 8 cores and the /9 for the number of jobs is a saturating choice. The slave 192.168.2.102 is set to run at most 2 compile jobs to keep its load low, even if its CPU has 4 cores. The XBPS_MAKEJOBS setting is increased to 16 to account for the possible parallelism (2 + 9 + 2 + some slack).

Distfiles mirror(s)

In etc/conf you may optionally define a mirror or a list of mirrors to search for distfiles.

$ echo 'XBPS_DISTFILES_MIRROR="ftp://192.168.100.5/gentoo/distfiles"' >> etc/conf

If more than one mirror is to be searched, you can either specify multiple URLs separated with blanks, or add to the variable like this

$ echo 'XBPS_DISTFILES_MIRROR+=" https://sources.voidlinux.org/"' >> etc/conf

Make sure to put the blank after the first double quote in this case.

The mirrors are searched in order for the distfiles to build a package until the checksum of the downloaded file matches the one specified in the template.

Ultimately, if no mirror carries the distfile, or in case all downloads failed the checksum verification, the original download location is used.

If you use uchroot for your XBPS_CHROOT_CMD, you may also specify a local path using the file:// prefix or simply an absolute path on your build host (e.g. /mnt/distfiles). Mirror locations specified this way are bind mounted inside the chroot environment under $XBPS_MASTERDIR and searched for distfiles just the same as remote locations.

Cross compiling packages for a target architecture

Currently xbps-src can cross build packages for some target architectures with a cross compiler. The supported target is shown with ./xbps-src -h.

If a source package has been adapted to be cross buildable xbps-src will automatically build the binary package(s) with a simple command:

$ ./xbps-src -a <target> pkg <pkgname>

If the build for whatever reason fails, might be a new build issue or simply because it hasn't been adapted to be cross compiled.

Using xbps-src in a foreign Linux distribution

xbps-src can be used in any recent Linux distribution matching the CPU architecture.

To use xbps-src in your Linux distribution use the following instructions. Let's start downloading the xbps static binaries:

$ wget http://alpha.de.repo.voidlinux.org/static/xbps-static-latest.<arch>-musl.tar.xz
$ mkdir ~/XBPS
$ tar xvf xbps-static-latest.<arch>-musl.tar.xz -C ~/XBPS
$ export PATH=~/XBPS/usr/bin:$PATH

If your system does not support user namespaces, a privileged group is required to be able to use xbps-uchroot(1) with xbps-src, by default it's set to the xbuilder group, change this to your desired group:

# chown root:<group> ~/XBPS/usr/bin/xbps-uchroot.static
# chmod 4750 ~/XBPS/usr/bin/xbps-uchroot.static

Clone the void-packages git repository:

$ git clone git://github.com/void-linux/void-packages

and xbps-src should be fully functional; just start the bootstrap process, i.e:

$ ./xbps-src binary-bootstrap

The default masterdir is created in the current working directory, i.e void-packages/masterdir.

Remaking the masterdir

If for some reason you must update xbps-src and the bootstrap-update target is not enough, it's possible to recreate a masterdir with two simple commands (please note that zap keeps your ccache/distcc/host directories intact):

$ ./xbps-src zap
$ ./xbps-src binary-bootstrap

Keeping your masterdir uptodate

Sometimes the bootstrap packages must be updated to the latest available version in repositories, this is accomplished with the bootstrap-update target:

$ ./xbps-src bootstrap-update

Building 32bit packages on x86_64

Two ways are available to build 32bit packages on x86_64:

• cross compilation mode
• native mode with a 32bit masterdir

The first mode (cross compilation) is as easy as:

$ ./xbps-src -a i686 pkg ...

The second mode (native) needs a new x86 masterdir:

$ ./xbps-src -m masterdir-x86 binary-bootstrap i686
$ ./xbps-src -m masterdir-x86 ...

Building packages natively for the musl C library

Canonical way of building packages for same architecture but different C library is through dedicated masterdir. To build for x86_64-musl on glibc x86_64 system, prepare a new masterdir with the musl packages:

$ ./xbps-src -m masterdir-x86_64-musl binary-bootstrap x86_64-musl

Your new masterdir is now ready to build packages natively for the musl C library:

$ ./xbps-src -m masterdir-x86_64-musl pkg ...

Building void base-system from scratch

To rebuild all packages in base-system for your native architecture:

$ ./xbps-src -N pkg base-system

It's also possible to cross compile everything from scratch:

$ ./xbps-src -a <target> -N pkg base-system

Once the build has finished, you can specify the path to the local repository to void-mklive, i.e:

# cd void-mklive
# make
# ./mklive.sh ... -r /path/to/hostdir/binpkgs