The data was some MB and the error message when I did the push was
fatal: The remote end hung up unexpectedly error: RPC failed; result=55, HTTP code = 0
If you get this error, it's because you are trying to push a large delta to the repository and your push buffer is not big as needed.
The solution is to increase your buffer size with this command:
git config http.postBuffer 1024000
This will add a line in your config file with the specified value.
Set the value to what you need.
The http.postBuffer configuration value is exactly the maximum size in bytes of the buffer used by smart HTTP transports when POSTing data to the remote system (source).