export https_proxy="https://my-proxy.com:443"
export http_proxy="https://my-proxy.com:80"
sudo vim /etc/yum.conf
add proxy on first line proxy=https://my-proxy.com:80
[main]
proxy=https://my-proxy.com:80
keepcache=0
debuglevel=2
logfile=/var/log/yum.log
...
sudo rm -f /etc/yum.repos.d/bintray-rpm.repo
curl -L https://www.scala-sbt.org/sbt-rpm.repo > sbt-rpm.repo
sudo mv sbt-rpm.repo /etc/yum.repos.d/
sudo yum install sbt