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Comment by Arainach | Hacker News Reader

How do you consider the UX "nearly identical" or "arguably worse"?

The Mercurial CLI has clear, well named commands that are predictable and easy to memorize. hg histedit is clean and easy to use and visually shows you what is going to happen - what the new order will be - nondestructively.

The Git CLI requires you to understand its internal data structures to understand the difference between a rebase and a merge, and most people still can't explain it.

I've worked with Mercurial for 5+ years and no one on my team has ever given up on a client and done rm -rf to start anew. Every single git user I've talked to has done that multiple times.

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> How do you consider the UX "nearly identical" or "arguably worse"?

The core concept is similar -- history is a stream of content-addressed commits. Concepts map almost 1:1. git does some things arguably better.

> hg histedit is clean and easy to use and visually shows you what is going to happen - what the new order will be - nondestructively.

hg histedit is basically identical to git rebase -i. The names are different, but the operations end up being more or less the same. hg amend -> git commit --amend. Graft -> cherry-pick.

> I've worked with Mercurial for 5+ years and no one on my team has ever given up on a client and done rm -rf to start anew. Every single git user I've talked to has done that multiple times.

I don't know what to tell you. I've also worked with Mercurial for 5+ years, but I've never rm -rf'd a git repo.

> history is a stream of content-addressed commits

Not quite true for mercurial. You also get stable identifiers for commits that remain the same even after being manipulated such as after rebases or amends. It also enables tracking the evolution of a changeset which then enables `hg evolve`.

Being content addressable isn’t a desirable feature in a user-friendly version control system. Who cares about it? Giving stable identifiers to commits is a much more needed feature.

You mean "git tag"?

If you tag every commit, sure. You don't know which commit has a bug that needs to be fixed in advance. And at the point you're tagging every commit, you're fighting git.

EDIT: reconsidering: you would have to move a tag when you make changes. A tag is just giving a name to a commit, not a stable identifier that follows a change. A branch is a more appropriate analogy.

A git-native workflow for this would be to have a sequence of branches you continue to update, where 'main' is those branches merged at all times.

When you fix bugs, you don't edit history, you treat these as new features.

Correct. The comparable git workflow when you fix a bug is that the work goes on the branch of the feature the bug was in, and "main" is updated to use the new head of that branch.

Have you used Jujutsu before? It's git-backed and it sounds like it incorporates a lot of these niceties from Mercurial. I find it an awful lot more intuitive than Git to use and the stable identifiers are absolutely lovely to have.

Of course I use jj every day. In fact it improves on mercurial by eliminating the need to run `hg evolve` because it just auto-evolves for you.

I've never had much contact with Mercurial myself, so are there any features from Mercurial that JJ doesn't already incorporate? Or any differences you find interesting?

git rebase -i drops you into a text editor where you have to manually copy, move, and edit lines, knowing what words mean what and manually type them each time.

hg histedit gives you a TUI which shows an interactive list and allows quick manipulation with the arrow keys and single characters for actions.

The two are as "equivalent" as i3 and KDE.

I don't know what version of hg you're using, but the histedit I've used drops me into an identical text editing setup as git rebase -i. It includes a summary of what the verbs mean in a comment at the bottom.

Interesting. The curses interface for histedit has been around since 2019, and I had no idea it wasn't the default since it's dramatically nicer to work with: https://www.mercurial-scm.org/relnotes/4.9

> The Git CLI requires you to understand its internal data structures to understand the difference between a rebase and a merge, and most people still can't explain it.

I don't know anything about mercurial, but is it really too much to ask of software engineers to understand a DAG (the only "internal data structure" in question)?

About rm -rf ing a repo, I'm sure if mercurial was more popular it would also suffer from the types of coders that would do such things on a regular basis.

> About rm -rf ing a repo, I'm sure if mercurial was more popular it would also suffer from the types of coders that would do such things on a regular basis.

Nope. You are simply flat-out wrong.

I have taught Mercurial to CEOs, secretaries, artists, craftsmen, etc. It just worked. They understood the mental model and happily used it to protect their stuff. The people I taught Mercurial to who worked with CNC machines in particular loved Mercurial as it protected them against changing some wonky setting in their CAD program that screwed everything up that they somehow couldn't figure out how to restore.

Git I can barely even explain to CS majors. The fact that AI has so much training data and is so very, very good at explaining how to undo strange Git states is all the evidence you need for just how abjectly terribly the Git UX is.

Jujutsu has proven that the underlying structure of Git is acceptable and that the issues really are all about the UX.

Well I can explain git to anybody who understands a DAG. And mercurial is also based on the exact same data structure. So yes it would be very surprising if you didn't consider it to be "acceptable".

The fact that there's lots of training data out there on strange git states is proof of exactly my point. Git is popular and thus used by lots of people who don't know the first thing about the command line, let alone data structures. Had mercurial won you'd see exactly the same types of errors commonly appearing.

Mercurial doesn't require understanding a DAG.

You can get by with `hg next`, `hg prev`, and `hg rebase -s <from> -d <to>` to move entire chains of commits around. Commands with obvious names that allow moving around without understanding chains of dependencies. No weird states where you checkout an old commit but random files from where you just were are left in the directory tree for you to deal with. No difference between `checkout`, `reset --soft`, and `reset --hard` to remember. No detached head states.

And no, `HEAD~1` is not a replacement for `prev`. One is a shortening of "previous", one requires you to remember a magic constant based on knowledge of the DAG.

As for `hg next`, the various responses here should show how clear, obvious, and intuitive the git UI is: https://stackoverflow.com/questions/6759791/how-do-i-move-fo...

I disagree that Mercurial users can use `hg rebase -s ... -d ...` without understanding a DAG. The mechanism is only meaningful if you understand the structure of the commit graph.

Look, I'm not commenting on which system has better named commands. My main points are

1) A DAG is not a difficult concept to understand (despite the "scary" name). If you can understand package dependencies or a manufacturing process you already understand it.

2) Learning git without knowing about the DAG, i.e. knowing what a commit even is, is counterproductive. It's like learning to drive a manual car without knowing what the clutch does. Sure you could probably teach someone that way, but why would you? What's the benefit to learning mercurial without understanding what a rebase actually does?

If I spend a couple hours reading I can understand how git works, but I'm going to forget an hour later because it is so damn complicated with all the different details that my brain flushes it's cache to make room for something with less violently confusing edge cases.

For understanding git internals I went through "Git from the bottom up", a simple document with examples you type in, just to see what's going on. Many of those examples are raw git commands, nothing as sophisticated as "git commit". Easy to read, doesn't take long, but leaves behind an understanding that isn't maybe fully obvious at the time but makes everything much easier, forever. I've recommended that method to many coworkers and it seems to work well for most people. It doesn't need hours of reading either.

> Well I can explain git to anybody who understands a DAG.

This. Right here. This is the difference.

I can explain Mercurial to people who don't want to understand a DAG.

For non-professional developers, the "merge machinery" is completely worthless.

The difference is that Mercurial lets you duck it until you need it while Git slaps you in the face with it at every commit.

For the non-professional developer, the flow is "commit, commit, commit, commit, whoops--how many commits do I need to go back to fix things?, oh, 2, okay--revert, commit, commit, commit, commit, ...

At no point in their day are they facing "merge". And that makes all the difference.

The non-professional flow you described does not require merging in git either. I suppose most teaching resources about git go deep into merging because it was created for distributed development where that's important, but it doesn't mean you have to teach it to a non-professional like that.

Not that I think mercurial didn't have "simpler" UI back then, but the arguments thrown around in this thread are pretty bollocks.

> Git I can barely even explain to CS majors.

Considering the number of kids that I've managed to understand git, I think this might be a teaching issue.

> The Mercurial CLI has clear, well named commands that are predictable and easy to memorize.

Precisely this. I've been stuck using git since 2010 and to this day I have a large git-cheatsheet doc which I need to reference any time I need to do anything beyond the daily add+commit+push. The git commands make zero sense and are just about impossible to remember because they make no sense.

In contrast, I've never felt a need for a cheatsheet doc for mercurial commands.

> done rm -rf to start anew. Every single git user I've talked to has done that multiple times.

Indeed! Of all the source control tools I've used, git is the only one where I regulary need to do a tarball of the src repo before doing any uncommon operations because there is a non-zero chance it'll go into some unrecoverable state and need to start over.

I've never rm-rf'ed a git repo (why would you voluntarily remove the reflog?) while also being a very mid-tier developer. The types that do also tend to reboot machines every time something goes wrong instead of looking for the exact cause of the problem and fixing it once and for all; to screw around with SQL (move subqueries here or there, add and remove indexes at random) until it runs acceptably instead of building proper understanding of how their database works, and so on. At least judging by what I've seen. Not really something to be proud of.

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