There are two basic cases when we push our local repo to remote repo. These two cases differ in their settings. But sometimes, we are easily confused.

First scenario#

The first case is that you have created a local repo and want to store it on GitHub later. In this case, your usual work flow for local repo is:

1. Initialize the local repo (git init)
2. Write you code and document, etc.
3. Add changes to index (e.g., git add . )
4. Commit the changes (git commit -m "some message")
5. Repeat step 2 – 4

Then, at some point, you want to push this local repo to GitHub. First, you need to create a new repo in GitHub. But be careful that you should not create a README file in this repo.

If you do create a README file, you will encounter errors when you try to push to this remote repo:

hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

If you try to pull from the remote repo to fix the above error, you will then see error message such as:

fatal: refusing to merge unrelated histories

In order to spare yourself from these troubles, just do not create a README file! Just create an empty repo.

After you have created an empty remote repo, you should add it as one of your remote. You can then push to it smoothly.

git remote add upstream <your_repo_url>
git push upstream master

If you accidentally created it README file, you can also force to push to this remote repo:

git push -f upstream master

The above option -f will erase the commit on the remote repo. You can then force push to the remote repo.

Second scenario#

The other case is that you already have a remote repo¹ and you want to continue to develop it locally. In this case, you should first clone this remote repo and then develop it locally.

git clone <your_remote_repo>

After cloning this remote repo, you can develop it locally. In this case, you do not have to manually add this repo as your remote. It will be added as your remote by default with the name origin.

In order to push to this repo, we use the following command:

References#

• https://stackoverflow.com/questions/17291995/push-existing-project-into-github
• https://stackoverflow.com/questions/23304688/issue-pushing-to-a-github-repository-created-with-initialize-repo-with-a-readme