Bug#1061772: RFP: jujutsu -- Git-compatible VCS that is both simple and powerful

[Blair Noctis]

On Mon, 29 Jan 2024 10:08:29 -0500 Antoine Beaupre  wrote:
> Package: wnpp
> Severity: wishlist
> X-Debbugs-Cc: debian-r...@lists.debian.org
> 
> * Package name: jujutsu
>   Version : 0.13.0
>   Upstream Contact: Martin von Zweigbergk 
> * URL : https://martinvonz.github.io/jj/
> * License : Apache-2.0
>   Programming Lang: Rust
>   Description : Git-compatible VCS that is both simple and powerful

For packager information, the CLI has changed to be the jj-cli crate; the
jujutsu one has a notice saying that.

Also it requires the gix stack, which is still a huge pain point.

-- 
Sdrager,
Blair Noctis


OpenPGP_signature.asc
Description: OpenPGP digital signature

Bug#1061772: RFP: jujutsu -- Git-compatible VCS that is both simple and powerful

[Antoine Beaupre]

Package: wnpp
Severity: wishlist
X-Debbugs-Cc: debian-r...@lists.debian.org

* Package name: jujutsu
  Version : 0.13.0
  Upstream Contact: Martin von Zweigbergk 
* URL : https://martinvonz.github.io/jj/
* License : Apache-2.0
  Programming Lang: Rust
  Description : Git-compatible VCS that is both simple and powerful

Jujutsu is a powerful version control system for software
projects. You use it to get a copy of your code, track changes to the
code, and finally publish those changes for others to see and use. It
is designed from the ground up to be easy to use—whether you're new or
experienced, working on brand new projects alone, or large scale
software projects with large histories and teams.

Jujutsu is unlike most other systems, because internally it abstracts
the user interface and version control algorithms from the storage
systems used to serve your content. This allows it to serve as a VCS
with many possible physical backends, that may have their own data or
networking models—like Mercurial or Breezy, or hybrid systems like
Google's cloud-based design, Piper/CitC.

Today, we use Git repositories as a storage layer to serve and track
content, making it compatible with many of your favorite Git-based
tools, right now! All core developers use Jujutsu to develop Jujutsu,
right here on GitHub. But it should hopefully work with your favorite
Git forges, too.

We combine many distinct design choices and concepts from other
version control systems into a single tool. Some of those sources of
inspiration include:

 * Git: We make an effort to be fast—with a snappy UX, efficient
   algorithms, correct data structures, and good-old-fashioned
   attention to detail. The default storage backend uses Git
   repositories for "physical storage", for wide interoperability and
   ease of onboarding.

 * Mercurial & Sapling: There are many Mercurial-inspired features,
   such as the revset language to select commits. There is no explicit
   index or staging area. Branches are "anonymous" like Mercurial, so
   you don't need to make up a name for each small change. Primitives
   for rewriting history are powerful and simple. Formatting output is
   done with a robust template language that can be configured by the
   user.

 * Pijul & Darcs: Jujutsu keeps track of conflicts as first-class
   objects in its model; they are first-class in the same way commits
   are, while alternatives like Git simply think of conflicts as
   textual diffs. While not as rigorous as systems like Darcs and
   Pijul (which are based on a formalized theory of patches, as
   opposed to snapshots), the effect is that many forms of conflict
   resolution can be performed and propagated automatically.

And it adds several innovative, useful features of its own:

 * Working-copy-as-a-commit: Changes to files are recorded
   automatically as normal commits, and amended on every subsequent
   change. This "snapshot" design simplifies the user-facing data
   model (commits are the only visible object), simplifies internal
   algorithms, and completely subsumes features like Git's stashes or
   the index/staging-area.

 * Operation log & undo: Jujutsu records every operation that is
   performed on the repository, from commits, to pulls, to
   pushes. This makes debugging problems like "what just happened?" or
   "how did I end up here?" easier, especially when you're helping
   your coworker answer those questions about their repository! And
   because everything is recorded, you can undo that mistake you just
   made with ease. Version control has finally entered the 1960s!

 * Automatic rebase and conflict resolution: When you modify a commit,
   every descendent is automatically rebased on top of the
   freshly-modified one. This makes "patch-based" workflows a
   breeze. If you resolve a conflict in a commit, the resolution of
   that conflict is also propagated through descendants as well. In
   effect, this is a completely transparent version of git rebase
   --update-refs combined with git rerere, supported by design.

[!WARNING] The following features are available for use, but experimental; they 
may have bugs, backwards incompatible storage changes, and user-interface 
changes!

 * Safe, concurrent replication: Have you ever wanted to store your
   version controlled repositories inside a Dropbox folder? Or
   continuously backup repositories to S3? No? Well, now you can!

   The fundamental problem with using filesystems like Dropbox and
   backup tools like rsync on your typical Git/Mercurial repositories
   is that that they rely on local filesystem operations being atomic,
   serialized, and non-concurrent with respect to other reads and
   writes—which is not true when operating on distributed file
   systems, or when operations like concurrent file copies (for
   backup) happen while lock files are being held.

   Jujutsu is instead designed to be safe under