# Getting started with Git development

This section and the next describe in detail how to set up git for working with the SciPy source code. If you have git already set up, skip to Development workflow.

## Basic Git setup

- Developing with git can be done entirely without GitHub. Git is a distributed version control system. In order to use git on your machine you must first install git.

- Introduce yourself to Git:

      git config --global user.email you@yourdomain.example.com
      git config --global user.name "Your Name Comes Here"

## Making your own copy (fork) of SciPy

You need to do this only once.

1. Set up and configure a github account

   If you don’t have a github account, go to the github page, and make one.

   You then need to configure your account to allow write access - see the `Generating SSH keys` help on github help.

2. Next, create your own forked copy of SciPy.

### Overview

    git clone https://github.com/your-user-name/scipy.git
    cd scipy
    git remote add upstream https://github.com/scipy/scipy.git
    git submodule update --init

### In detail

#### Clone your fork

1. Clone your fork to the local computer with `git clone https://github.com/your-user-name/scipy.git`

2. Investigate. Change directory to your new repo: `cd scipy`. Then `git branch -a` to show you all branches. You’ll get something like:

       * main
       remotes/origin/main

   This tells you that you are currently on the `main` branch, and that you also have a `remote` connection to `origin/main`. What remote repository is `remote/origin`? Try `git remote -v` to see the URLs for the remote. They will point to your github fork.

   Now you want to connect to the upstream SciPy github repository, so you can merge in changes from trunk.

#### Linking your repository to the upstream repo

    cd scipy
    git remote add upstream https://github.com/scipy/scipy.git

`upstream` here is just the arbitrary name we’re using to refer to the main SciPy repository at SciPy github.

Just for your own satisfaction, show yourself that you now have a new ‘remote’, with `git remote -v show`, giving you something like:

    upstream     https://github.com/scipy/scipy.git (fetch)
    upstream     https://github.com/scipy/scipy.git (push)
    origin       https://github.com/your-user-name/scipy.git (fetch)
    origin       https://github.com/your-user-name/scipy.git (push)

To keep in sync with changes in SciPy, you want to set up your repository so it pulls from `upstream` by default. This can be done with:

    git config branch.main.remote upstream
    git config branch.main.merge refs/heads/main

Your config file should now look something like (from `$ cat .git/config`):

    [core]
            repositoryformatversion = 0
            filemode = true
            bare = false
            logallrefupdates = true
            ignorecase = true
            precomposeunicode = false
    [remote "origin"]
            url = https://github.com/your-user-name/scipy.git
            fetch = +refs/heads/*:refs/remotes/origin/*
    [remote "upstream"]
            url = https://github.com/scipy/scipy.git
            fetch = +refs/heads/*:refs/remotes/upstream/*
    [branch "main"]
            remote = upstream
            merge = refs/heads/main

#### Update submodules

Initialize git submodules:

    git submodule update --init

This fetches and updates any submodules that SciPy needs (such as Boost).

### Next steps

You are now ready to start developing with SciPy. Check the SciPy contributor guide for more details.