I get UNABLE_TO_VERIFY_LEAF_SIGNATURE error when trying to install hexo-cli on Windows. I tried to switch to another mirror, but this did not fix the problem.
UNABLE_TO_VERIFY_LEAF_SIGNATURE
Are you for a corporate proxy? They most likely intercept MiTM traffic with a self-signed SSL certificate.
A hacker solution is simply to disable SSL for NPM
npm set strict-ssl false
More detailed instructions can be found here: How to fix SSL certificate error when starting Npm on Windows?
References:
https://github.com/Medium/phantomjs#i-am-behind-a-corporate-proxy-that-uses-self-signed-ssl-certificates-to-intercept-encrypted-traffic
https://security.stackexchange.com/questions/101721/is-it-possible-for-corporation-to-intercept-and-decrypt-ssl-tls-traffic