- Git repository and branches
- Using Vagrant
- Building manually
- More information
- Related pages
You will need to clone the Tails Git repository, and to checkout the
branch that you want to build. This branch should be based on
devel (most likely, not
more about our Git branches layout.
Tails can be built easily in a virtual machine using Rake, Vagrant and vagrant-libvirt. The process requires the KVM virtual machine hypervisor to be available, a minimum of 512 MiB of free memory and a maximum of 20 GB of free storage.
For details how Vagrant is setup, see its design page.
If you run Debian Jessie, you must install a few dependencies from Debian Stretch, and one of Tails' repos until Debian bug #823395 is fixed:
sudo tee /etc/apt/sources.list.d/stretch.list <<EOF deb http://ftp.us.debian.org/debian/ stretch main deb-src http://ftp.us.debian.org/debian/ stretch main EOF sudo tee /etc/apt/preferences.d/vagrant-libvirt-from-stretch.pref <<EOF Package: * Pin: release o=Debian,n=stretch Pin-Priority: 100 Package: vagrant vagrant-libvirt ruby-excon ruby-fog-core ruby-fog-libvirt ruby-fog-xml Pin: release o=Debian,n=stretch Pin-Priority: 990 EOF sudo apt-key add config/chroot_sources/tails.chroot.gpg sudo tee /etc/apt/sources.list.d/builder-jessie.list <<EOF deb http://deb.tails.boum.org/ builder-jessie main deb-src http://deb.tails.boum.org/ builder-jessie main EOF sudo apt-get update
Now we can install all the dependencies:
sudo apt-get install \ git \ rake \ libvirt-daemon-system \ dnsmasq-base \ ebtables \ qemu-system-x86 \ qemu-utils \ vagrant \ vagrant-libvirt sudo systemctl restart libvirtd
Make sure that the user that is supposed to initiate the build command
is part of the
for group in kvm libvirt libvirt-qemu; do sudo adduser $USER $group; done
Then reboot the system (alternatively, if you know what you are doing,
newgrp and reload the
If Vagrant failed to start the Tails builder VM the first time (e.g. because of permission issues or the
kvmmodule not veing loaded) it will not automatically run the provisioning script, so you must run
rake vm:provisionyourself before attempting your first
rake build. If that fails, run
rake vm:destroy, which removes this half-broken VM, and then start from scratch with
rake buildor similar.
ruby-fog-libvirt <= 0.0.3has a bug that will make Vagrant crash when trying to start the VM if you have any libvirt domain defined with a floppy (
fd) as part of the boot order, set via
<os>tag; please remove all such occurrences! If you really need to have a floppy as part of some domain's boot order, please set it via
<boot order='1'/>which does not trigger the bug.
If the system you are setting this up on ever had the old (Virtualbox-based) Vagrant setup, you will get errors unless you clean up these parts:
Remove any old pinnings for
ruby-net-ssh. If you followed our old instructions to the point, that should be:
sudo rm /etc/apt/preferences.d/tails-build-vagrant
Clearing the Vagrant configuration seems to also often solve issues:
rm -r ~/.vagrant.d
Once all dependencies are installed, get the Tails sources and checkout the development branch:
git clone https://git-tails.immerda.ch/tails cd tails git checkout devel
Build Tails using Vagrant:
The first time, this can take a little while to download the base virtual
machine from Tails mirror (around 300 MB). It will then boot the machine,
set it up and start the build process. When done, several
should appear in the current directory.
After you are done working on Tails, do not forget to shut the virtual machine down:
One may also want to customize their image before building.
To know all available Rake tasks, please run
If you have a local HTTP proxy, the build system will use it as long as
you properly set the
http_proxy environment variable. The easiest way to
do so is to run:
... and then, pass the
extproxy build option (see below).
This needs to be done before any other operations.
Options regarding the build process can be set using the
TAILS_BUILD_OPTIONS environment variable. Multiple options must be
separated by whitespaces.
The following options are available:
Tails builds way faster when everything is done in memory. If your computer runs Linux and happens to have more than 7 GB of free memory before you start the virtual machine, it will automatically switch to 'build in RAM' mode.
To force a specific behaviour please set:
- ram: start the virtual machine with 7 GB of memory, build Tails
tmpfs. Build fails if the system is not in a proper state to do so.
- noram: start the virtual machine with 512 MB of memory if not already done, build Tails using the virtual machine hard disk.
Building Tails requires downloading a little bit more than 1 GB of Debian packages. To preserve bandwidth and developer sanity, using a HTTP proxy is nearly a must. Tails virtual machine contains a fully configured local HTTP proxy that will be used if no other local proxy is defined.
The following flags can be used to force a specific behaviour:
- extproxy: use the proxy configured through the
http_proxyenvironment variable. Fail if it is not set.
- vmproxy: use the local proxy configured in the virtual machine even if a local HTTP proxy is set.
- noproxy: do not use any HTTP proxy.
One of the most expensive operations when building Tails is the creation
of the final SquashFS. It also depends on the compression algorithm used.
When working on the
testing branch, the image will be made
using the slow but efficient default. Any other setup will switch to the
Forcing a specific behaviour can be done using:
- gzipcomp: always use gzip to create the SquashFS.
- defaultcomp: always use the default compression algorithm.
Some operations are preserved accross builds. Currently they are:
- The wiki (for documentation).
In case you want to delete all these, the following option is available:
- cleanall: force a clean up before starting the build.
The number of virtual CPUs that are allocated in the virtual machine can be customized through:
- cpus=n: allocate n CPUs to the virtual machine.
Obviously you should not allocate more virtual CPUs than the number of cores available to the host system. When using Linux, the number of CPUs allocated will default to be the same as the host system.
The build system can only work on files that have been committed to the Git repository. By default, it will refuse to start a build in presence of uncommitted changes. This behaviour can be controlled by:
- ignorechanges: allow to make a build that will ignore changes in the Git repository.
The fastest build you could pretend to get can be done by setting:
export TAILS_BUILD_OPTIONS="ram cache extproxy gzipcomp"
This will force the build to happen in RAM and allow skipping the boostrap stage if one is cached, and will use use an HTTP proxy external to the virtual machine, and SquashFS compression will be done using gzip.
In order to build Tails manually, you need a running Debian Jessie system and some backports. Anything else will fail.
The following Debian packages need to be installed:
live-build2.x package, adapted for Wheezy and later. Its version is something like 3.0.5+really+is+2.0.12-0.tails2. One can install it from:
deb http://deb.tails.boum.org/ builder-jessie main
This APT repository's signing key can be found:
- in our Git tree (that you have cloned already, right?):
- at http://deb.tails.boum.org/key.asc
- on the keyservers.
It is certified by the Tails signing key, and its fingerprint is:
221F 9A3C 6FA3 E09E 182E 060B C798 8EA7 A358 D82E
You should pin that repository, so that live-build isn't upgraded to the version of jessie.
#/etc/apt/preferences.d/00-builder-jessie-pinning Package: * Pin: release o=Debian,a=stable Pin-Priority: 700 Package: * Pin: origin deb.tails.boum.org Pin-Priority: 800
Then install these dependencies from Jessie:
apt-get install \ dpkg-dev \ eatmydata \ gettext \ ikiwiki \ intltool \ libfile-slurp-perl \ liblist-moreutils-perl \ libyaml-libyaml-perl \ libyaml-perl \ libyaml-syck-perl \ perlmagick \ po4a \ syslinux-utils \ time \ whois
And install these dependencies from jessie-backports (please verify manually that the following command actually does install the expected versions):
apt-get install \ debootstrap/jessie-backports
- in our Git tree (that you have cloned already, right?):
Remove any line matching
Every build command must be run as
root, at the root of a clone of the
tails repository. A local HTTP proxy is required.
In short, a build shall be done using:
lb clean --all && lb config --apt-http-proxy http://localhost:3142 && lb build
lb config or
lb build in an environment that wasn't full
cleaned first is not supported.
If you need to set custom build settings that are specific to your local environment, such as a custom Debian mirror or APT proxy, you probably want to configure live-build a bit.
The most common customizations are documented on this wiki:
- to avoid compressing the SquashFS using XZ (efficient, but very
export MKSQUASHFS_OPTIONS='-comp gzip'in your build environment;
- to avoid downloading lots of Debian packages during every build, you
can use apt-cacher-ng; however, the build system
constantly switches APT sources for our
APT repositories, so some custom
configuration is needed to make
apt-cacher-nguseful: see the bits about
More documentation about this can be found in the Debian Live Manual.
More documentation about the build process can be found in the Debian Live Manual.