Working with Phantom and git

Make sure you have the git version control system installed.

Getting your first copy

Once you have a GitHub account, you must create your own fork. This is done using the “fork” button (the big button on top right of the repo page). You can then clone your fork to your computer:

git clone

This gets a copy of the entire phantom repository. Obviously replace USERNAME with your GitHub username.

Setting your username and email address

Before you can push changes, you must ensure that your name and email address are set, as follows:

cd phantom
git config --global "Joe Bloggs"
git config --global ""

Please use your full name in the format above, as this is what appears in the commit logs (and in the AUTHORS file)

Receiving updates from your fork

Procedure is: stash your changes, pull the updates, reapply your changes:

git stash
git pull
git stash pop

Receiving updates from the master branch

Before you can receive updates from the master branch, you must first link your fork to the master branch:

git remote add upstream

This only needs to be done once.

To update, the procedure is: stash your changes, pull the updates, reapply your changes:

git stash
git fetch upstream
git merge upstream/master
git stash pop

This will update your fork on your local machine only.

Committing changes to your fork

Submit changes to Phantom carefully! The first thing is to pull any upstream changes as described above. Once you have done this, first check what you will commit:

git diff

then go through each subset of changes you have made and commit the file(s) with a message:

git commit -m 'changed units in dim file for problem x' src/main/dim_myprob.f90

and so on, for all the files that you want to commit. Then, when you’re ready to push the changeset back to your fork use:

git push

Note that you will only be allowed to push changes if you have already updated your copy to the latest version.

If you have just updated your code from the master repo, simply update your fork via:

git commit -m 'merge'
git push

This will push all the remote changes to your forked version of Phantom.

Committing changes to the master branch

This is done through a “pull request”. To do this, you can click the “contribute” button on the GitHub page to request that your changes be pulled into the master copy of Phantom. Please do this frequently. Many small pull requests are much better than one giant pull request!

Automated tests will be performed on all pull requests to ensure nothing gets broken. Once these pass and the code has been reviewed, the code can be merged.