A version control system is an accurate audit trail of everything that has happened in the repository. Every create, delete, rename, every rwx mode change, every content change.
In BitKeeper files work like they do in Unix, there is a (globally) unique name for each file object. Where the object lives in the repository is an attribute of that object, as are the contents, the permissions, who has changed etc.
Here's a super common workflow that's easy in BitKeeper and miserable in Git. I'm debugging an assert. I want to see who added the assert. I pop into the gui that shows me the per file graph and contents, search for the assert, hover over the rev and see that it was done a long time ago. I look in the area above the assert and I see a recent change, hover over that, see the comments and go "hmm, maybe this". Double click that line and I pop into a different gui that shows me the whole commit that contains that suspect line.
Note that because I have a graph per file, I have checkin comments per file. More work for you poor committers but a godsend for us debuggers. More breadcrumbs are more better.
In Git, less breadcrumbs, single commit message. Git wants to go from the rev to the commit, it's miserable to look around in a file and then go backwards to the commit.
When I was supporting BitKeeper our average response time to bug report or a crash report was 25 minute. 24x7. The only reason it was that long was because we were all in North America so there was a window where we were all asleep. Response time 6am-6pm PST was typically under 5 minutes. And I credit the fact that the tool accurately recorded everything and you could find the history really easily.
Oh, and it didn't slow down as the repo got big. Git is fine in little repos but it sucks pretty hard in big ones. Sucks even worse if you are on NFS. I can dig up benchmarks, we built up a synthetic 4M file repo and ran a bunch of tests on it (it was a modified version of the facebook repo builder, the facebook one had some stuff in it that made Git look incredibly bad, we looked at that and decided that wasn't real world or fair, we took that part out).
> Here's a super common workflow that's easy in BitKeeper and miserable in Git. I'm debugging an assert. I want to see who added the assert. I pop into the gui that shows me the per file graph and contents, search for the assert, hover over the rev and see that it was done a long time ago. I look in the area above the assert and I see a recent change, hover over that, see the comments and go "hmm, maybe this". Double click that line and I pop into a different gui that shows me the whole commit that contains that suspect line.
I may be misunderstanding that particular workflow (I'm sadly unfamiliar with bitkeeper), but this seems like a workflow that I accomplish relatively often with the use of tig[1].
On a separate note: thank you for the wonderfully detailed reply. It's such a pleasure to have an opposing view be so thoroughly explained.
Indeed, there are many tools to do that with git. I use vim with vim-fugitive (:Gblame, then o to open the commit I want to look at), but most IDEs do that to.
Heh, no worries dude (or dudette), I have dealt with the trolls. You can't post that the sky is blue without getting the trolls telling you are doing it wrong.
Every day humans make me again realize that I love my dogs, and respect my dogs, more than humans. There are exceptions but they are few and far between.
> In Git, less breadcrumbs, single commit message. Git wants to go from the rev to the commit, it's miserable to look around in a file and then go backwards to the commit.
A thought not universally shared. Intel was our biggest customer and when they saw the quality of the breadcrumbs produced by our gui check in tool vs the command line checkins they were smart enough to push hard that everyone used the guis.
I get why, as a dev, you want git commit -m'Fixed bug' but as the debugger guy, the reviewer gui, anyone who reads the code, that's a horrible thing to do to those readers.
Who, if you wait long enough, will be you. And I'll laugh my ass off at all the lazy committers who really could use more breadcrumbs when they have to debug their code later.
Been there, done that, I haven't worked with people that lazy in decades.
edit: since HN won't let me extend the thread, let me reply to the comment below because BK does do something special.
The GUI for checkins presents you with a list of files, a place to type comments, and a big pane that shows the diffs. You type in comments for the first file, go to the next, type in comments (yes, there is a way to say use the previous comments). As you move from file to file, the bottom pane shows the diffs for that file so you can see what changed in that file.
The special sauce, that Git most definitely does not have, is when you get to the last file, which in BK is the ChangeSet file, this is where you would type the commit message. What are the diffs? There aren't any so we stuff all the comments you just typed on individual files. What does that do? Well, on the files you are usually typing in details of how you did this or that, when you get to all of those comments, you naturally uplevel and type in why you were doing all that.
It dramatically increases the usefulness of commit messages. That's why Intel pretty much mandated the use of the gui checkin vs the command line checkin.
To anyone reading, bitkeeper does nothing special in this regard. Enforce commit message standards, plenty of platforms and systems built around git (and literally every other SCM) have support for this.
It's possibly the least interesting and least unique selling point an SCM can have. It's really funny that you keep bringing up this example around the thread.
EDIT: To respond to the above edit:
Again, he's Proving The Point. Commits should be atomic. If you have to individually comment on file changes then the correct thing to do would be to put those in their own commit, no? I'm not really sure what's being described is necessarily a cool feature, but rather a way to avoid making sure your changes are truly related. I honestly don't see the point. This seems like a feature that was written because of the decisions that were made into how BitKeeper works internally, not because it's a fantastic idea. You can get the same thing with atomic commits in git. You comment per file, because BK tracks changes per file. Git does not do this. You should be making your commits atomic because git is tracking the actual content. Atomic commits will accurately describe what's being changed, and then of course those all get lumped together in a patch/PR.
Git isn't lacking the feature you're describing, it just kind of is there without any extra data tracking required, because it's not making up for technical design decisions.
In BitKeeper files work like they do in Unix, there is a (globally) unique name for each file object. Where the object lives in the repository is an attribute of that object, as are the contents, the permissions, who has changed etc.
Here's a super common workflow that's easy in BitKeeper and miserable in Git. I'm debugging an assert. I want to see who added the assert. I pop into the gui that shows me the per file graph and contents, search for the assert, hover over the rev and see that it was done a long time ago. I look in the area above the assert and I see a recent change, hover over that, see the comments and go "hmm, maybe this". Double click that line and I pop into a different gui that shows me the whole commit that contains that suspect line.
Note that because I have a graph per file, I have checkin comments per file. More work for you poor committers but a godsend for us debuggers. More breadcrumbs are more better.
In Git, less breadcrumbs, single commit message. Git wants to go from the rev to the commit, it's miserable to look around in a file and then go backwards to the commit.
When I was supporting BitKeeper our average response time to bug report or a crash report was 25 minute. 24x7. The only reason it was that long was because we were all in North America so there was a window where we were all asleep. Response time 6am-6pm PST was typically under 5 minutes. And I credit the fact that the tool accurately recorded everything and you could find the history really easily.
Oh, and it didn't slow down as the repo got big. Git is fine in little repos but it sucks pretty hard in big ones. Sucks even worse if you are on NFS. I can dig up benchmarks, we built up a synthetic 4M file repo and ran a bunch of tests on it (it was a modified version of the facebook repo builder, the facebook one had some stuff in it that made Git look incredibly bad, we looked at that and decided that wasn't real world or fair, we took that part out).