This document lists changes to the pkg-go workflow which the pkg-go team has agreed on.

1. 2017-11 changes

1.1. “upstream” branch should contain upstream git history

TODO: describe the rationale and workflow, and how to deal with nonfree and vendored files

Migration

  1. Add upstream repository as a new remote. Then fetch its history.

    git remote add up https://github.com/paultag/go-topsort
    git fetch up
  2. Delete/Rename the old upstream branch, and checkout a new upstream branch.

    git branch -m upstream old/upstream
    git checkout -b upstream up/master
  3. Merge upstream history into the packaging branch, at the same point where the previous upstream was, usually based on release tags if upstream does releases; otherwise, the Debian release number will contain the commit ID.

    git diff <upstream_commit_id> old/upstream  # should be no differences
    git checkout master
    git merge --allow-unrelated-histories <upstream_commit_id>

Packaging new upstream release

When packaging new upstream release, you can fetch upstream remote and merge it into upstream branch.

If upstream does tag release, you can merge the new tag into upstream branch, and create a new tag with upstream/<version> format, which will be used by gbp.

git fetch up
git checkout upstream
git merge <upstream_tag>
git tag -a upstream/<version>
git checkout master
git merge upstream/<version>

If upstream doesn’t have tags, you can merge the latest commit into upstream branch, and create the upstream/<version> tag by commit date and id.

git fetch up
git checkout upstream
git merge up/master
TAG=$(git log --date=format:%Y%m%d --pretty=upstream/0.0_git%cd.%h -1)
git tag -a "$TAG"
git checkout master
git merge "$TAG"

1.2. Drop pristine-tar branches

Rationale

The appeal of using pristine-tar was that a byte-for-byte equal orig tarball could be easily (and automatically) generated, preventing rejected uploads and aiding future historians with reproducibly rebuilding older versions. Further, using pristine-tar results in a self-contained git repository which makes for a simple mental model (as opposed to the git repository + orig tarball in parent directory model).

In reality, pristine-tar branches weren’t consistently updated across our repositories for a number of reasons, resulting in despised additional maintenance effort for little benefit (uploads may or may not be rejected, depending on the repository state).

Hence, even though the new gbp push command and a consistent setting of pristine-tar=True in debian/gbp.conf might help improve consistency, we decided to abandon pristine-tar altogether.

Old workflow

  • Obtain a byte-for-byte equal orig .tar.gz file: pristine-tar list and pristine-tar checkout

  • Build against a byte-for-byte equal orig .tar.gz file: enable gbp buildpackage’s pristine-tar option, e.g. via --git-pristine-tar or pristine-tar=True in debian/gbp.conf.

New workflow

  • Obtain a byte-for-byte equal orig .tar.gz file: origtargz(1)

  • Build against a byte-for-byte equal orig .tar.gz file: use origtargz before building

Note
Using --git-upstream-tree=TAG (the default) is not sufficient to obtain a byte-for-byte equal orig .tar.gz file. In stapelberg’s tests, only 5% of pkg-go’s git repositories would match the orig .tar.gz in the archive.
Tip

Configure gbp-clone(1) to automatically run origtargz(1) by adding the following to ~/.gbp.conf:

[clone]
postclone=origtargz

Migration

  1. Remove any pristine-tar-related settings from this repository’s gbp config files, defaulting to pristine-tar=False:

    for f in .gbp.conf debian/gbp.conf .git/gbp.conf
    do
        [ -e "$f" ] && sed -i '/^pristine-tar/d' "$f"
    done
  2. Delete the pristine-tar branch: git push origin :pristine-tar

TODO: verify step 2 works

1.3. Auto-format debian/control

Rationale

Common formatting increases consistency between packages maintained by pkg-go and auto-formatting frees up time previously spent on manual formatting.

Old workflow

Manually format control files such as debian/control.

New workflow

Use wrap-and-sort(1) from the devscripts package in the root of the Debian package directory:

wrap-and-sort --wrap-always --trailing-comma

The command line arguments result in a format which produces minimal diffs whenever new values are added or old values are removed.

TODO: is there any editor integration for wrap-and-sort yet?

Tip

To auto-format before committing, create the following hook at .git/hooks/pre-commit:

#!/bin/sh
wrap-and-sort --wrap-always --trailing-comma

Migration

  1. Run wrap-and-sort --wrap-always --trailing-comma

1.4. Adopt DEP-14 branch naming

Rationale

Consistency in our branch naming makes it easier for team-internal and team-external contributors to understand/interact with our packaging repositories.

Old workflow

The default branch of a package was named master.

New workflow

See DEP-14 for the full text. In a nutshell:

  • The default branch of a package should be named debian/sid.

  • git HEAD should point to debian/sid.

  • The upstream git history should live in a branch named upstream.

    TODO: wait until discussion in #812721 came to an agreement

  • Packages which release into stable releases should use the codename of the target distribution, e.g. debian/stretch.

Migration

  1. TODO: describe the branch rename.

  2. git symbolic-ref HEAD refs/heads/debian/sid

1.5. Derive debian/changelog from git history

Rationale

Some pkg-go repositories used the old workflow, some used the new workflow — this was just a personal preference of whoever last touched the repository.

Unifying this difference eases contributions to any pkg-go repository.

Old workflow

  • Document your changes in a pending debian/changelog entry with the special suite name UNRELEASED.

  • Document your changes in your git commit(s).

New workflow

  • Document your changes in your git commit(s).

  • Before uploading the package to Debian, use gbp dch -R --commit.

TODO(stapelberg): install https://paste.debian.net/hidden/c3a81ddf/ (git update hook which declines old-workflow d/changelog updates) in all pkg-go repositories

Migration

TODO: remove pending d/changelog entries from existing packages.