See: https://www.sslshopper.com/ssl-checker.html#hostname=www.haskell.org This is causing curl to fail to download it: ezyang@sabre:~/Downloads$ curl https://www.haskell.org/cabal/release/cabal-install-1.24.0.0/cabal-install-1... curl: (60) server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none More details here: http://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. Apologies if this is the wrong list. Thanks, Edward