Test environment

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Testing your ebuilds (see also Package testing) can be a tedious task. Beside a simple re-emerge of the package in question, to see whether it merges successfully, a good testing practice usually needs to take one or more of the following questions into account:

Having a clean gentoo installation to test with: Using your day to day desktop, might miss on dependencies, which you happen to have installed already and thus producing false positives, i.e. letting your ebuild successfully install, while on a new system it would have been failed due to missing dependencies.
An exhaustive testing of all possible USE flag combinations: For ebuilds with only a few USE flags, this can be done easily by hand. For packages with a lot of USE flags, such an approach is error-prone. You might be better by writing a shell or python script to enumerate all the possibilities.
Profile testing: Here testing of default vs. hardened and multilib vs. no-multilib profiles is of interest. It may for example uncover problems with PIC/PIE code in hardened profiles or problems of missing proper multiclassing in the ebuild. Usually you don't want to switch profiles just for the purpose of testing an ebuild.
Keyword testing: This requires the proper hardware and is done by the arch projects.

So to run proper and efficient tests for your ebuild, a dedicated test environment seems necessary. There are several options for this, like using a chroot environment, VM's, a containerized enviroment or even dedicated hardware. The table below summarizes some of the pros and cons of these options.

Method	Pros	Cons
chroot guide	fast setup small memory footprint	need to reset the environment after each emerge
chroot using btrfs	fast setup small memory footprint	needs btrfs need to reset the environment after each emerge
Virtual Machine	easy to set up from a live DVD snapshots can be used to avoid reinstallation	large memory footprint
Container	fast setup re-usable (with some work) safe OpenRC <-> Systemd

Using Docker containers for ebuild testing with ebuildtester

ebuildtester is a Python script for testing ebuilds in a Docker container.

ebuildtester compiles a docker container with the parameters passed at invocation time and either installs the specified package or puts the user into a shell inside the container.

Usage of the script is simple, go to the ebuildtester article for more details.

Using LXC containers for ebuild testing

These instructions make use of unprivileged LXC containers.

user $lxc-create -t download -n proxy-maint

Then for Distribution, choose gentoo; Release, choose current; and Architecture, choose amd64.

When it completes, start up the container with,

user $lxc-start -n proxy-maint

Then configure a basic development environment using the recommended tools.

FILE /etc/portage/sets/tools

# tools
app-crypt/gnupg
app-editors/vim # or just symlink busybox to `/usr/local/bin/vi` and update your environment variables.
app-portage/tatt
dev-vcs/git
dev-util/pkgcheck
dev-util/pkgdev

user $lxc-console -n proxy-maint

root #emerge --ask @tools

To stop the container,

user $lxc-stop -n proxy-maint

To clone the container for working on a particular ebuild,

user $lxc-copy -n proxy-maint -N "${PN}" # clones the original container

To delete it when finished,

user $lxc-destroy -n "${PN}" # destroy the container when finished

Using Kubler for ebuild testing

See Kubler for more info.

Kubler may be used to develop against any ebuild repository.

Create a new namespace, let's call it edev:

user $kubler new namespace edev

Create a new builder, select kubler/bob as IMAGE_PARENT:

user $kubler new builder edev/bob

Edit the new builder's build.sh and add any additional repositories:

Note
For ::gentoo only there's no need to add the repo, it's already available; binding in the development fork and updating .bashrc is probably desirable, however.

FILE /config/build.sh

configure_builder() {
    # we overwrite this with a local host mount later, but this takes care of the initial overlay setup in the builder for us
    add_overlay kubler https://github.com/edannenberg/kubler-overlay.git
    # just for convenience
    echo 'cd /var/db/repos/kubler' >> ~/.bashrc
}

Create a new image, let's call it bench, use kubler/bash as IMAGE_PARENT:

user $kubler new image edev/bench

Edit the new image's build.conf and configure the builder and ebuild repo to be mounted builder:

FILE /config/build.conf

BUILDER="edev/bob"
BUILDER_MOUNTS=(
    "/data/development/ebuild-repos/gentoo:/var/db/repos/gentoo"
    "/data/development/ebuild-repos/kubler-overlay:/var/db/repos/kubler"
)

Start an interactive build container and get tinkering:

user $kubler build -i edev/bench

root #ebuild dev-lang/foo/foo-0.4.0.ebuild manifest merge

Test environment

Contents

Using Docker containers for ebuild testing with ebuildtester

Using LXC containers for ebuild testing

Using Kubler for ebuild testing

See also