'sbt cli' runs on Linux, but not windows - there are failures due to the way the echo command is used to inject XML text into the stdin of the CLI. The echo command in MS Windows does not work the same way as Linux echo. (BTW: Linux echo is deprecated, and should be using bash printf instead).
The command echo '<x/>' fails on windows. The can't tolerate the < or > characters, and various quoting attempts don't seem to be able to overcome this.
Installing cygwin, and running sbt cli from the cygwin bash shell is not alone sufficient to fix this problem. Probably PATH settings and/or other environment variables are required to be set up.
Instructions about installing Cygwin have been removed from the Wiki for now, as they are not needed to get regular old 'sbt test' to work.