On the Mac, brew install something (chromedriver in this case), yields:
curl: (51) SSL: certificate verification failed (result: 5)
Error: Failed to download resource "chromedriver"
Download failed: https://chromedriver.storage.googleapis.com/2.22/chromedriver_mac32.zip
Que pasa?
Env var SSL_CERT_FILE was set to something by some other tool previously. This ...
export SSL_CERT_FILE=""
brew install something
... fixes the problem
来源：https://stackoverflow.com/questions/38737490/curl-certificate-verification-failed-on-mac