Re-opening per TimToady's comments: http://irclog.perlgeek.de/perl6/2016-07-21#i_12881470
The map de-lazifies when sunk, but in this case the for's sinking doesn't seem to propagate to the map. This, for example, prints all the values: m: for ^3 { ^10 .map: *.say; Nil }; say 42; -- Cheers, ZZ | https://twitter.com/zoffix