scalaxb installed via cs creates an exception when run, scopt dependency appears incorrect

[aappddeevv]

Installed scalaxb via conscript 0.4.4. When run, I get an exception based on scopt:

$ scalaxb 
java.lang.NoClassDefFoundError: scopt/OptionParser
    at scalaxb.compiler.Main$.start(Main.scala:50)
    at scalaxb.compiler.SbtApp.run(SbtApp.scala:8)
    at xsbt.boot.Launch$$anonfun$run$1.apply(Launch.scala:109)
    at xsbt.boot.Launch$.withContextLoader(Launch.scala:128)
    at xsbt.boot.Launch$.run(Launch.scala:109)
    at xsbt.boot.Launch$$anonfun$apply$1.apply(Launch.scala:35)
    at xsbt.boot.Launch$.launch(Launch.scala:117)
    at xsbt.boot.Launch$.apply(Launch.scala:18)
    at xsbt.boot.Boot$.runImpl(Boot.scala:41)
    at xsbt.boot.Boot$.main(Boot.scala:17)
    at xsbt.boot.Boot.main(Boot.scala)
Caused by: java.lang.ClassNotFoundException: scopt.OptionParser
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 11 more
Error during sbt execution: java.lang.NoClassDefFoundError: scopt/OptionParser