1. Problem description

Homebrew has a problem installing GIT

curl: (60) SSL certificate problem: certificate has expired More details here: https://curl.haxx.se/docs/sslcerts.html
If you'd like to turn off curl's verification of the certificate, use the -k (or --insecure) option. 
HTTPS-proxy has similar options --proxy-cacert and --proxy-insecure.
Error: Failed to download resource "pcre2"

Probably because homebrew has not been updated for a long time, the local certificate has expired.

2. Solution

echo insecure >> ~/.curlrc
HOMEBREW_CURLRC=1
export HOMEBREW_CURLRC
#brew install git