Crash stepping in Script Object script

Pasted this in a new script document. Compiled, switched to Debugging, tried to step in.
————

script foo
property y : 5
to test(x)
return x
end test
end script

property parent : foo

test(y) --> 5

————
Instant crash with apple crash reporter (https://www.dropbox.com/s/7qehswmzarj8mui/2019-02-13-ObjectCrash.txt?dl=0)

My E-Mail address is ed.stockly@latimes.com, in case you want to get back to me.
–> Script Debugger 7.0.6 (7A69) (Updating now)
–> Mac OS 10.11.6 (15G22010)

Exact same behavior in

–> Script Debugger 7.0.7 (7A72)
–> Mac OS 10.11.6 (15G22010)

This is an AppleScript crash. You’ve created a circular script object parent relationship and AppleScript does not defend against this. This will crash in the Script Editor as well.

Dang. OK. I was going to say it happened after relaunching.

Funny thing is that script came directly from a tutorial on MacScripter on using Script Objects.

It’s like the 6th sample down.

script foo
   property y : 5
   to test(x)
       return x
   end test
end script

property parent : foo

test(y) --> 5

I wonder how it’s supposed to look.

(While I’m at it does anyone know a good source for a tutorial on using script objects that’s not a crashy as the one on MacScripter?)

https://www.macscripter.net/viewtopic.php?pid=96390#p96390