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Git Adoption Soaring; Are There Good Migration Strategies?
Got To Get Me A Git writes "Distributed version control systems (DVCS) seem to be the next big thing for open source software development. Many projects have already adopted a DVCS and many others are in the process of migrating. There are a lot of major advantages to using a DVCS, but the task of migrating from one system to another appears to be a formidable challenge. The Perl Foundation's recent switch to Git took over a year to execute. The GNOME project is planning its own migration strategy right now after discovering that a significant majority of the project's developers favor Git. Perhaps some of the projects that are working on transitions from other mainstream version control systems can pool their resources and collaborate to make some standardized tools and migration best practices documentation. Does such a thing already exist? Are any folks out there in the Slashsphere working on migrating their own project or company to a DVCS? I'd appreciate some feedback from other readers about what works and what doesn't."
It's more than just an moron, it's an nasty, stubborn, selfsentered and selfish moron.
"Our neighbour is an right old git" could be used to describe an elderly neigbour who, say, regularly blocked your driveway because your car got in the way of the sunlight on his garden.
The old neighbour from Dennis, or Victor Meldrew from One Food In The Grave are both fine examples of gits.
It's like a weaker version of the c-word.
If the system you are migrating from manages trees, you should be fine. CVS migration is pretty easy and I understand that Perforce works quite well too (in both directions!). Most of the migration tools are listed in the GIT FAQ.
The places where people are likely to have trouble is migrating from tools that don't understand that there's more than one file. For example, RCS and SCCS both support branches, but in a completely different way to git (branches are per-file, they're not for the whole repository). This means that during conversion, something useful has to happen with them, but the right answer isn't clear to a program. If versions 1.1, 1.1.1.1, 1.1.1.2 and 1.2 of file "foo" exist, then versions 1.1.1.2 and 1.2 are on different branches and either may be the older revision. It's not clear if revision 1.43.1.3 of file "bar" is the same "branch" as "foo" 1.1.1.2 or not. Because RCS and SCCS deal with single files only, it's not possible to find an answer to these questions in the history files at all - if there is an answer, it's just a convention of the user. Essentially what's happening here is that the git import process requires information which isn't represented in the files you're converting from. For what it's worth, migrating from SCCS or RCS to CVS has a similar problem.
Personally, I've migrated from CVS to git for findutils (well, Jim Meyering did the actual migration; he migrated coreutils too). I haven't regretted migrating at all. It took me a long time of using git locally before I was comfortable migrating the master repo, though. As a git beginner the thing I found most worrying was that I found it hard to envisage the effect of the git command I was typing. The thing it took me a long time to figure out is that with a distributed version control system, it's safe to screw up your local copy, as long as you don't push the result.
Quoth Linus Torvalds, "I'm an egotistical bastard, and I name all my projects after myself. First Linux, now git." :)
Audioscrobbler
I'll pray for your soul. There's nothing worse than a group of managers who think that the world will get better when Clearcase is employed. I swear, that tool seems to be deliberately designed to slow you down.
Git or BK command :
git pull
Clearcase command :
cleartool findmerge -avobs -fversion MYLABEL -merge -gmerge
Some things git is bad at:
- no of partial cloning, so a big history means lots of stuff to download, this is especially bad when it comes to binary files
- no way to download just a single file or directory, a user always has to clone the whole repository
I curse more when I use git than when I use Windoz (and those are the only times I curse). Git's design is really that bad (from a user perspective).
Git is fully distributed (with no "authoritative" source), but it doesn't give you any tools understand/manage the distribution of files. If you have a work group with more than a few people, you are constantly asking what repo (and what access method to it), what branch, and what (bombastically long) revision. It's fine for 1-2 people, but then any version control system is fine for a small enough group.
The documentation helps little. When you do "git help merge", you don't @#$@# care that this is the front end to multiple merge methods. You just want the stupid thing to work. If it's a special case, then you'll look for an advanced technique; but you are stuck reading through all this crap trying to figure out what really matters. No offense to the people working on git docs. It used to be awful, now it just sucks. The problem is more in the user interface design than the docs.
There are over 100 git commands, and a command can do radically different things depending the the switches and target syntax. It's more confusing than any other revision control system that I have worked with.
I use git because I have to, not because I want to (like Windoz). After using it for months, I still routinely get stuck trying to figure out the right mix of commands, arguments, and target syntax needed to get common things done.
Git can do some (nice) things that subversion can't, but it creates so many problems that you haven't gained anything.
I've heard good things about mecurial and bazaar. I wouldn't recommend git to anyone I liked (but it's perfect for perl :-).