You can meet SSL certificate problem problem on Company or private nework place. The error is like under text.
$ git clone https://github.com/pynvme/pynvme Cloning into 'pynvme'... fatal: unable to access 'https://github.com/pynvme/pynvme/': SSL certificate problem: unable to get local issuer certificate
You can solve this problme using this command. I’ll hope solve your problem!
$ git config --global http.sslVerify false