The -m <namespace> argument to boot run is required.

[phreed]

https://github.com/danielsz/system/blob/master/src/system/boot.clj#L81
The issue is that > boot run results in a java.lang.NullPointerException.
This is because the namespace argument is not optional.
A couple things could be done to correct the problem.
The most obvious is to check to see if the namespace is supplied and report with the help if it is not.