On Fri, 17 Mar 2017 21:09:12 +0100, Sönke Ludwig wrote: 

Starting computation in main task
Starting to compute value in worker task.
Finished computation in main task. Waiting for async value.
CoreTaskFiber was terminated unexpectedly: Joining tasks in foreign threads is currently not supported.
Program exited with code 255

Any chance this could get fixed? I was seriously relying on this feature working; it was mentioned the introductory book as working, and the online docs don't indicate a difficultly, so I incorrectly thought async was working.

This should be fixed/implemented for the new vibe-core package, which
is not yet the default in 0.8.0. Try adding this to the package recipe
to force using vibe-core: 

dependency "vibe-d:core" version="~>0.8.0-beta"
subConfiguration "vibe-d:core" "vibe-core"

I tried this, paranoiacally ran dub upgrade and dub --force and got the same error.