# Vendored Dependencies

Dependencies are almost all vendored in at the standard Go `/vendor` path. This allows
people to build go-ethereum using the standard toolchain without any particular package
manager. It also plays nicely with `go get`, not requiring external code to be relied on.

The one single dependent package missing from `vendor` is `golang.org/x/net/context`. As
this is a package exposed via public library APIs, it must not be vendored as dependent
code woulnd't be able to instantiate.

To allow reproducible builds of go-ethereum nonetheless that don't need network access
during build time to fetch `golang.org/x/net/context`, a version was copied into our repo
at the very specific `/build/_vendor` path, which is added automatically by all CI build
scripts and the makefile too.

# Debian Packaging

Tagged releases and develop branch commits are available as installable Debian packages
for Ubuntu. Packages are built for the all Ubuntu versions which are supported by
Canonical:

- Trusty Tahr (14.04 LTS)
- Wily Werewolf (15.10)
- Xenial Xerus (16.04 LTS)
- Yakkety Yak (16.10)

Packages of develop branch commits have suffix -unstable and cannot be installed alongside
the stable version. Switching between release streams requires user intervention.

The packages are built and served by launchpad.net. We generate a Debian source package
for each distribution and upload it. Their builder picks up the source package, builds it
and installs the new version into the PPA repository. Launchpad requires a valid signature
by a team member for source package uploads. The signing key is stored in an environment
variable which Travis CI makes available to certain builds.

We want to build go-ethereum with the most recent version of Go, irrespective of the Go
version that is available in the main Ubuntu repository. In order to make this possible,
our PPA depends on the ~gophers/ubuntu/archive PPA. Our source package build-depends on
golang-1.7, which is co-installable alongside the regular golang package. PPA dependencies
can be edited at https://launchpad.net/%7Elp-fjl/+archive/ubuntu/geth-ci-testing/+edit-dependencies

## Building Packages Locally (for testing)

You need to run Ubuntu to do test packaging.

Add the gophers PPA and install Go 1.7 and Debian packaging tools:

    $ sudo apt-add-repository ppa:gophers/ubuntu/archive
    $ sudo apt-get update
    $ sudo apt-get install build-essential golang-1.7 devscripts debhelper

Create the source packages:

    $ go run build/ci.go debsrc -workdir dist

Then go into the source package directory for your running distribution and build the package:

    $ cd dist/ethereum-unstable-1.5.0+xenial
    $ dpkg-buildpackage

Built packages are placed in the dist/ directory.

    $ cd ..
    $ dpkg-deb -c geth-unstable_1.5.0+xenial_amd64.deb
