Today I ran into this error:
jj5@mercy:~/public-git$ git push origin master error: gnutls_handshake() failed: A TLS warning alert has been received. while accessing https://email@example.com/public/git/info/refs
The solution, of all things, was to add a ServerName spec into my Apache configuration file /etc/apache2/sites-enabled/default-ssl.conf, e.g.:
Great! It works!