Git Good, By Playing A Gamified Version Of Git

What better way to learn to use Git than a gamified interface that visualizes every change? That’s the idea behind Oh My Git! which aims to teach players all about the popular version control system that underpins so many modern software projects.

Git good, with a gameified git interface.

Sometimes the downside to a tool being so ubiquitous is that it tends to be taken for granted that everyone already knows how to use it, and those starting entirely from scratch can be left unsure where to begin. That’s what creators [bleeptrack] and [blinry] had in mind with Oh My Git! which is freely available for Linux, Windows, and macOS.

The idea is to use a fun playing-card interface to not only teach players the different features, but also to build intuitive familiarity for operations like merging and rebasing by visualizing in real-time the changes a player’s actions make.

The game is made with beginners in mind, with the first two (short) levels establishing that managing multiple versions of a file can quickly become unwieldy without help. Enter git — which the game explains is essentially a time machine — and it’s off to the races.

It might be aimed at beginners, but more advanced users can learn a helpful trick or two. The game isn’t some weird pseudo-git simulator, either. The back end uses real git repositories, with a real shell and git interface behind it all. Prefer to type commands in directly instead of using the playing card interface? Go right ahead!

Oh My Git! uses the free and open-source Godot game engine (not to be confused with the Godot machine, a chaos-based random number generator.)

diagram of the radicle node-to-node connectivity

Radicle: An Open-Source, Peer-to-Peer, GitHub Alternative

The actions of certain large social networks have recently highlighted how a small number of people possess significant power over the masses and how this power is sometimes misused. Consequently, there has been a surge in the development of federated (or decentralized) services, such as Mastodon and Matrix.  But what about development? While GitHub and similar services are less likely to be used for political manipulation, they are still centralized services with a common failure point. Radicle is an open-source, peer-to-peer collaboration stack built on top of Git but backed with public key cryptography as a standard and a gossip protocol to ensure widespread data sharing across the network and, thus, some fault tolerance.

Essentially, code and associated documentation are secured cryptographically with an identity. The Git protocol is used for actual data transfer from peer-to-peer, which means that updates are only sent as deltas, not complete copies, maximizing channel bandwidth efficiency. A custom gossip protocol is used for metadata transfer around the network of peers. The projects had a local-first ideology, with users running a full-stack node on their hardware and all features available, even offline, which is great for laptop users who move around locations with sporadic access to the internet.

Judging from their Zulipchat instance, this is a highly active space, so perhaps it is worth diving in and seeing if it floats your boat. Fancy getting onto the Fediverse, but only have a spare MS-DOS machine to try it on? We’ve got it covered. Want to use Git but not online? You need a private Git server. Finally, too much Git? How about Gitless?

Thanks [Anonymous] for the tip! No, that wasn’t lost on us :D

Linux Fu: Deep Git Rebasing

If you spend much time helping people with word processor programs, you’ll find that many people don’t really use much of the product. They type, change fonts, save, and print. But cross-references? Indexing? Largely, those parts of the program go unused. I’ve noticed the same thing with Git. We all use it constantly. But do we? You clone a repo. Work on it. Maybe switch branches and create a pull request. That’s about 80% of what you want to do under normal circumstances. But what if you want to do something out of the ordinary? Git is very flexible, but you do have to know the magic incantations.

For example, suppose you mess up a commit message — we never do that, of course, but just pretend. Or you accidentally added a file you didn’t want in the commit. Git has some very useful ways to deal with situations like this, especially the interactive rebase.

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Too Much Git? Try Gitless

Git has been a powerful tool for software development and version control since the mid ’00s, gaining widespread popularity since then. Originally built by none other than Linus Torvalds for handling Linux kernel development, it’s branched out for use with all kinds of other projects. That being said, it is not the easiest thing to learn how to use, with tons of options, abstract ideas, and non-linear workflows to keep track of. So if you’re new to the system or don’t need all of its vast swath of features, you might want to try out an alternative like Gitless.

Thanks to the fact that the original Git is open source, it’s free to modify and use as any user sees fit, and there are plenty of options available. This one aims to simplify many of the features found in the original Git, implementing a tracking system which somewhat automates commits. It also includes a simplified branching system, making it easier to switch between branches and keep better track of all that’s happening in a project. The command line interface is simplified as well, and the entire system is backwards-compatible with Git which means that if you find yourself needing some of the more advanced tools it’s possible to switch between them with relative ease.

For those of us keeping track of our own software projects, who don’t necessarily need the full feature set that the original Git has to offer, this could be a powerful tool that decreases the steep learning curve that Git is known for. It’s definitely a system work diving into, though, regardless of whichever implementation you choose. It’s an effective tool for everything from complex, professional projects to small hobby projects on the Arduino.

This Week In Security: Git Deep Dive, Mailchimp, And SPF

First up, git has been audited. This was an effort sponsored by the Open Source Technology Improvement Fund (OSTIF), a non-profit working to improve the security of Open Source projects. The audit itself was done by researchers from X41 and GitLab, and two critical vulnerabilities were found, both caused by the same bad coding habit — using an int to hold buffer lengths.

On modern systems, a size_t is always unsigned, and the same bit length as the architecture bit-width. This is the proper data type for string and buffer lengths, as it is guaranteed not to overflow when handling lengths up to the maximum addressable memory on the system. On the other hand, an int is usually four bytes long and signed, with a maximum value of 2^31-1, or 2147483647 — about 2 GB. A big buffer, but not an unheard amount of data. Throw something that large at git, and it will break in unexpected ways.

Our first example is CVE-2022-23521, an out of bounds write caused by an int overflowing to negative. A .gitattributes file can be committed to a repository with a modified git client, and then checking out that repository will cause the num_attrs variable to overflow. Push the overflow all the way around to a small negative number, and git will then vastly under-allocate the attributes buffer, and write all that data past the end of the allocated buffer.

CVE-2022-41903 is another signed integer overflow, this time when a pretty print format gets abused to do something unexpected. Take a look at this block of code:

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GitHub ESP32 OTA Updates, Now In MicroPython Flavor

Wouldn’t it be great if you could keep all of your small Internet-connected hacks up to date with a single codebase? A couple of weeks ago, we wrote up a project that automagically pulls down OTA updates to an ESP32 from GitHub, using the ESP32 C SDK. [Pascal] asked in the comments, “but what about MicroPython?” Gauntlet thrown, [TURFPTAx] wrote ugit.pya simple library that mirrors all of the code from a public GitHub Python repo straight to your gizmo running Micropython.

[Damped] wrote in about Senko, another library that does something very similar, but by then [TURFPTAx] was already done. Bam! Part of the speed is that MicroPython includes everything you need to get the job done – parsing streamed JSON was the hard part with the original hack. MicroPython makes those sorts of things easy.

This is one of those ideas that’s just brilliant for a hacker with a small flock of independent devices to herd. And because itself is fairly simple and readable, if you need to customize it to do your own bidding, that’s no problem either. Just be sure that when you’re storing your WiFi authentication info, it’s not publicly displayed. ([TURFPTAx], could I log into your home WiFi?)

What’s [TURFPTAx] going to be using this for? We’re guessing it’s going to be deploying code to his awesome Open Muscle sensing rigs. What will we be using it for? Blinky Christmas decorations for the in-laws, now remotely updatable without them having to even learn what a “repo” is.

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Git Your PCBs Online

Last time, I’ve shown you how to create a local Git repository around your PCB project. That alone provides you with local backups, helping you never lose the changes you make to your files, and always be able to review the history of your project as it developed.

However, an even more significant part of Git’s usefulness is the ability to upload our creations to one of the various online Git repository hosting services, and keep it up to date at all times with a single shell command. I’d like to show you how to upload your project to GitHub and GitLab, in particular!

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