The archivesBaseName in build.gradle is later used to generate the .jar files, etc. Eventually, to make it easy for others to build against this library, you'll want to publish it to Maven. According to the Maven naming guidlines, you'll want only alpha-numeric numbers in those file names.

I have been helping people with builds and maven for a bit, and spaces and special characters cause all sorts of bothersom problems with the Java toolchain. Please rename it to "enchiridion2" or "Enchiridion2" without spaces.

You can safely use a more human readable name with spaces in the name field of the mcmod.info, and that's what will be displayed in info screens.

I have no intention to ever use maven.

Ok.

I hope you'll reconsider. You're already benefitting from Maven for your build environment, and it would be really great if you would use the same tools. I'm in the process of writing a tutorial on publishing with Maven on GitHub Pages, and having Enchiridion available to use with a 1-line change to build.gradle would be awesome.