Updating the package
====================

0. Update debcargo-conf.git so that cargo's dependencies are up-to-date. This
   means less stuff will have to be patched (in debian/debcargo-conf.patch) in
   the next step. This might take a while, ask other people for help if needed.
1. Empty d/make_orig_multi-pre-vendor.sh, then run d/make_orig_multi.sh <version>.

   If cargo-vendor tries to use too-new crates that debcargo-conf doesn't have
   patches for yet, downgrade them by tweaking d/make_orig_multi-pre-vendor.sh

   e.g. cargo update -p tempfile --precise 3.1.0

   You will need to have cargo-lock available
   $ cargo install cargo-lock --features=cli

2. Verify the -vendor component tarball to make sure it looks good.
   If not, edit d/make_orig_multi.sh and the surrounding files (such as patches
   and exclude files) and repeat the above until it looks good.
3. $ git fetch upstream
   You might have to first run:
   $ git remote add upstream https://github.com/rust-lang/cargo
4. $ git checkout debian/experimental
   $ gbp import-orig ../cargo_<version>.orig.tar.gz
   If you get errors, check the extra default flags in d/gbp.conf
5. Check that no old versions remain in vendor/. If there are, then your git
   repo was messed up when you ran (4). Rewind the debian/sid, upstream, and
   pristine-tar branches, delete the upstream/<version> tag; this reverts step
   (4). Clean up your git repo, and then try (4) again.
6. Update d/patches and the rest of the packaging, as normal.

General info
============

Cargo depends on a few hundred other crates (which themselves need cargo to
build). To avoid an insane bootstrapping loop, this package therefore embeds
all dependency crates. This is made convenient by the "vendor" subcommand.

(The alternative method, that expresses the true upstream dependencies more
faithfully, can be found in the "rust-cargo" crate, which is packaged just like
any other Debian Rust package. That is used as a library by the Debian packages
of various Rust ecosystem tools that build on top of cargo, such as our very
own debcargo. By contrast, this package is used as the actual executable
package manager, with a smaller bootstrapping requirement.)

As such, the original source is composed by two tarballs:
 * cargo source
 * dependencies crates (under vendor/), stripped of unused embedded C libraries