I was installing Clojure on a Mac running OS X Yosemite (10.10.5). Following the recommended procedure, I first installed Leiningen. While running lein deps
for the first time, I got a series of errors such as this:
Could not transfer artifact org.clojure:clojure:pom:1.8.0 from/to central (https://repo1.maven.org/maven2/): java.lang.RuntimeException: Unexpected error: java.security.InvalidAlgorithmParameterException: the trustAnchors parameter must be non-empty
The same baffling error message appears in a number of other StackOverflow questions relating to specific software other than Leiningen, Clojure, and OS X and the accepted answers in those cases appear to be very different from what worked for me (e.g. Error - trustAnchors parameter must be non-empty), so I have created a new question for this specific problem to help others trying to install Clojure on a Mac.