We need more eyes on https://bugs.dojotoolkit.org/ticket/18919 . With
the recent updates to Closure Compiler that were made (to allow users to
leverage more recent ES syntax), we've had reports of build regressions.
In our tests, we believe we've fixed these issues.
If you have a moment and could run a build on your code using 1.12 and
report back that would be greatly appreciated.