Crystal: `puts *{1}` causes instrumentation bug in playground

[Byron]

How to reproduce

Using crystal play, the bug occurs when the following code is entered:

puts *{1}

The error details as displayed in-app:

This is the output of crystal play

E, [2016-08-07 17:57:55 +0200 #49601] ERROR -- : Instrumention bug found (session=19, tag=101)

Meta

../crystal-lang/crystal/bin/crystal --version && sw_vers
Using compiled compiler at .build/crystal
Crystal 0.18.7+310 [671ecb3] (2016-08-07)
ProductName:    Mac OS X
ProductVersion: 10.11.6
BuildVersion:   15G31

[bcardiff]

@Byron, Thanks for having fun with the playground.

[Byron]

@bcardiff Thanks for showing how magical playgrounds for statically compiled languages can be, you are setting that bar there ! (*Says me, who also spent a few hours getting a docker-based Rust playground up and running locally. Actually, you should remove the play option, as it spoils people ;) *)