Another take, but more clumsy.

await2.lua

---
-- Fake synchronous functions
local function Sync(fn)
  
	local function make_resumer(co)
		return function(...)
			return assert(coroutine.resume(co, ...))
		end
	end

	local co = coroutine.create(fn)

	assert( coroutine.resume(co, make_resumer(co), coroutine.yield ) )
end

Sync(function(wait, yield)
	for i=1, 10 do
		console.log(i)
		setTimeout(wait, 1000)
		yield()
	end
end)

process:loop()