According to the description:
fatal: Could not read from remote repository
This should be a git error, indicating that there is no operation permission for the remote git library
(It is estimated that the git library path configuration is incorrect, otherwise it will not even have read permission)

If the problem is here, you can explore it as follows: (I am not sure whether using https git repository will cause this error)
Check the _config.yml file

deploy:
  type: git
  repository: git@github.com:username/username.github.io.git

correct

Then follow github’s git clone tutorial
https://help.github.com/articles/which-remote-url-should-i-use/
Use ssh mode and configure the ssh key.

Delete .deploy_git easily

Permission problem, you can change the directory, such as /User/hexoIt should be solved.