Don't import site. Don't permit default console encoding.
MODIFY
runtime/src/jycessing/Runner.java
runtime/src/jycessing/Runner.java
@@ -290,6 +290,9 @@ public class Runner {
// Suppress sys-package-manager output.
props.setProperty("python.verbose", "error");
+ // Prevent "Failed to install '': java.nio.charset.UnsupportedCharsetException: cp0."
+ props.put("python.console.encoding", "UTF-8");
+ props.put("python.import.site", "false");
// Can be handy for class loading issues and the like.
// props.setProperty("python.verbose", "debug");

Don't import site. Don't permit default console encoding.