workaround for old macOS versions, after change of Let's Encrypt root certificate --- see also https://letsencrypt.org/docs/dst-root-ca-x3-expiration-september-2021 --- Java/Scala Isabelle_System.download() works, but curl doens't;
#!/usr/bin/env bash
#
# dummy stty for old versions of scalac (e.g. 2.10.0)