Why should I have a version control system if I use time machine?

Question

I actually know that it's better to have an version control, but I wonder if Time Machine doesn't make a good job on this for lazy programmers?

Answer 1

They're actually very similar, but Time Machine doesn't keep track of what version of a file matches a particular build of the system. It's very useful to have the metadata.

Answer 2

Because TimeMachine won't track the log of file changes.

e.g. for a given file in Subversion I can easily determine when it changed, and what else changed at the same time.

It won't tell you who changed it, but I assume you're discussing single-user cases in this instance.

And finally you can't tie checkins and changes to builds/deployments.

Installing Subversion (or similar) on Mac OS is trivial, and won't consume resources unless you're checking in/out. It's strongly recommended. And of course make sure your repository is backed up with TimeMachine!

Answer 3

Time Machine will give you backups of your code. That's it.

Source Control will give this as well, but provides a lot more as well. The biggest is branching and merging, which is a huge help on projects.

Time Machine also won't store metadata like checkin comments, or who made what changes.

Finally, Time Machine can't really be distributed. If you want someone else to start working on your code as well then Time Machine won't help. But (good) source control would make collaboration very easy.

Answer 4

On the PC, active backup does pretty much the same thing, and also allows revision comparison albeit limited to file by file basis. The problem comes when you want to do something like list all the differences between version X and version Y, with the intention of building version Z based on a combination of the two. These type of backup systems are ok until you are simultaneously maintaining multiple versions of the same project.

Answer 5

Time Machine does not keep all backups (it only keeps hourly backups for a day, and only keeps daily backups for a month), so you will not have every version of the file if you need to go back and figure out exactly what change introduced a problem. It doesn't have diff support built in, though you could probably do a diff -r on the directories in question. It also does not record any commit messages, which can be invaluable in figuring out why someone changed the code in a particular way. Finally, it does not help you coordinate between multiple people or one person on multiple computers; one of the biggest benefits of version control is that it helps you distribute your code and merge in changes from multiple people.

If you want to have quick and easy version control, I'd recommend one of the distributed version control systems. Unlike centralized systems where you have to set up and administer a server, getting started with a distributed system is usually as easy as git init; git add .; git commit. I generally prefer Git, but Mercurial is also a good choice and some find it easier to get started with.

Answer 6

Branches & Tags?

Answer 7

For the reasons everybody else has pointed out, use source code control. It's easy to set up and will solve a lot of problems. It will tell you who changed what when, and why (if you use commit messages properly), and give you details. It's invaluable when you realize that something went wrong within the past few days.

Once you've done that, use Time Machine to keep backups of the repository. A version control system is not a backup system. Nothing is safe that is only on one file system.

Answer 8

The single most important and valuable thing in a version control repository is not the content, it's not even the history (that's #2), it's the commit messages. And you don't have those in a backup program.

Answer 9

dont forget about branching, it's one of most powerful tool a SCM can give you.. I dont know if time machine has some kind of 'alternate reality' feature