This page should contain information about how to work with ​git, specifically from the point of view of someone familiar with ​Subversion.

Common git tasks while working with ports

To start:

svn checkout https://svn.macports.org/repository/macports/trunk/dports

becomes

git clone git@github.com:macports/ports.git

When you clone you will get the entire history of the ports tree, with the latest version being checked out in the filesystem. After you make a change, you can run git status and get something like this.

On branch master
Your branch is up-to-date with 'origin/master'.
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

	modified:   aqua/iTerm2/Portfile

no changes added to commit (use "git add" and/or "git commit -a")

What this tells me, is that I've changed a Portfile, but not done anything. After that, you can add the files that you want to add to your commit using git add aqua/iTerm2/Portfile. Now, git status will look like:

On branch master
Your branch is up-to-date with 'origin/master'.
Changes to be committed:
  (use "git reset HEAD <file>..." to unstage)

	modified:   aqua/iTerm2/Portfile

Then run git commit and everything is set. On your machine. To push to github you then have to run git push.

Common git tasks while working with MacPorts base

Checking out a working copy

The source code of MacPorts itself is no longer managed in the same repository as all ports. Contrary to Subversion, checking out a sub-directory of a repository is not possible with Git. In order to avoid that all port maintainers have to clone the complete history of MacPorts base as well, the Subversion repository has been split into multiple separate repositories. MacPorts base is now available using

git clone git@github.com:macports/base.git # or
git clone https://github.com/macports/base.git # if SSH does not work on your network

See the section on repository splitting during the export to get an overview of where a path in the old Subversion history is now available in Git.

Committing changes in your working copy

A fundamental difference between Subversion and Git working copies is that svn commit by default commits all changes in your working copy, but git commit by default commits none. Git uses a staging area called "index" that allows you to mark changes for inclusion in the next commit. To add changes to the next commit, use

git add <filename>...

git status gives you an overview of the current index and your working copy. Additionally, it lists the commands to revert local uncommitted modifications (git checkout -- <filename>) and to remove files from the next commit, but preserve the modifications in your working copy (git reset HEAD <filename>).

Once you have chosen which files to include in your next commit using git add, it is a good practice to review this list using

git status

and show the diff to be committed using

git diff --cached

If you are not satisfied with your changes, you can keep changing your files. Note that you will have to add any new modifications to the index using git add again. Once you are satisfied with your change run

git commit

which prompts you for the commit message. See the section on commit messages in git for more information on git conventions and expectations in commit messages.

Because of Git's distributed nature, a commit on your local machine is not immediately available on the central server, like it was the case with Subversion. This means that you can continue to prepare further changes in additional commits before you publish your changes as a set. In fact, it is a very common practice in Git to do many small changes that are logically consistent in themselves and then publish them in one step.

If you have commit access, you can publish your commits using git push <remote-name> <branch-name>. <remote-name> is the name of the repository to which you want to push. The most common push target is the location you initially cloned, which is automatically named origin. <branch-name> is the name of the branch you want to push. The Git equivalent to Subversion's trunk is called master. In most cases you do not need to specify <remote-name> or <branch-name>:

git push

Common git tasks & notes about MacPorts' Subversion export

Commit messages

WIP

Repository split

WIP