github – Git, fatal: The remote end hung up unexpectedly

The problem is due to git/https buffer settings.
In order to solve it (taken from Git fails when pushing commit to github)

git config http.postBuffer 524288000

And run the command again

Cause : The default file post size for Git has been exceeded.

Solution :

Navigate to repo.

Run the following command to increase the buffer to 500MB after navigating to the repository:

git config http.postBuffer 524288000

This looks similar to How do I get github to default to ssh and not https for new repositories.
Probably its worth trying to switch from http protocol to ssh:

$ git remote add origin [email protected]:username/project.git