R – Introduction to Mercurial

dvcsmercurialversion-control

I have just begun working on a project which uses Mercurial as a version control system, and I need some basic tips on how to use this. Please use this question to give some introductory tips on this technology.

Especially, I am looking for tips on the best programs to use and the best techniques to use (branches, in and out-checking etc. I need to learn the best-practices!)

Best Solution

I know you already have the Mercurial site but the resource most useful to me was the Mercurial book. It's an excellent overview of the program and how to use it.

I found the best way to learn Mercurial was just to use it on a project. I imported into Mercurial a project I had exported from subversion and did some regular development with it. I made sure to clone the repository for different changesets so that I could get used to the merging and updating. I haven't learned all of the advanced uses but I'm now on a pretty firm footing with it and haven't switched back to Subversion yet.

A lot of projects have different techniques for commit workflow. Some have changes pushed from the developers, like centralized systems, and some will pull the changes from contributors (Linux, for example). It's hard to generalize too much without knowing the process for your project.

This is how I do my development:

  • Centralized tree on a file share or http, called project-trunk or project that is the definitive project version
  • A clean tree on my system that I clone from the remote repository and use to push back to the repository. I then clone from this tree for my changes. I call this tree project-local
  • Clone the project-local tree for each of my changes: eg. project-addusers, project-141, etc.
  • After I am finished with the commits to a tree, I then push the changes to the project-local repository
  • Finally, push the changes in the project-local to project-trunk

I have the clean project-local tree because then I can push all the changesets back to the trunk at one time, which is helpful if there is a group of related changes that need to push back together.

As for tools, it depends on your platform. I just use the vanilla command line tool. Coming from TortoiseSVN, it was a bit of a change to go to the command line. But I'm fine with it now. I tried using TortoiseHg but it didn't function well on my Windows 7 x64 virtual machine. I hear it's much better on the supported 32-bit platforms.