brew install yarn
错误信息如下：
$ brew install yarn Error: homebrew-core is a shallow clone. To `brew update` first run: git -C "/usr/local/Homebrew/Library/Taps/homebrew/homebrew-core" fetch --unshallow This restriction has been made on GitHub's request because updating shallow clones is an extremely expensive operation due to the tree layout and traffic of Homebrew/homebrew-core. We don't do this for you automatically to avoid repeatedly performing an expensive unshallow operation in CI systems (which should instead be fixed to not use shallow clones). Sorry for the inconvenience! ==> Downloading https://yarnpkg.com/downloads/1.17.3/yarn-v1.17.3.tar.g ######################################################################## 100.0% curl: (60) SSL certificate problem: certificate has expired More details here: https://curl.haxx.se/docs/sslcerts.html curl performs SSL certificate verification by default, using a "bundle" of Certificate Authority (CA) public keys (CA certs). If the default bundle file isn't adequate, you can specify an alternate file using the --cacert option. If this HTTPS server uses a certificate signed by a CA represented in the bundle, the certificate verification probably failed due to a problem with the certificate (it might be expired, or the name might not match the domain name in the URL). 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 "yarn" Download failed: https://yarnpkg.com/downloads/1.17.3/yarn-v1.17.3.tar.gz
使用npm安装yarn
npm install -g yarn