From @AlexDaniel

Code​:
sub foo { supply { emit($_) for 1..10; }; }; react { whenever foo() { next if $_ > 3; say $_; }; };

Result (2015.12)​:
1
2
3

Result (2016.08.1)​:
1
2
3
Access denied to keep/break this Promise; already vowed
  in any at /tmp/whateverable/rakudo-moar/a07a2e173cfc24f1bec549d2d5b79ef978e46b58/share/perl6/runtime/CORE.setting.moarvm line 1

Result (HEAD)​:
1
2
3
===SORRY!===
next without loop construct

It was supposed to work, I guess.

From @timo

Implemented `next` in f97d5c2aafc8427bfce1279438712e5f34498a4d, and added a pull request (#​998) for `redo` and `last`.

Seems like `next` used to work purely by accident, but now it's properly supported.

this is now testneeded.

The RT System itself - Status changed from 'new' to 'open'

From @zoffixznet

Tests in Raku/roast@af2d786d40

@zoffixznet - Status changed from 'open' to 'resolved'