NFD

This appears only on our Mac Mini, but I'm afraid it would start appearing elsewhere.

This error doesn't make sense for me. There is no "own initialization", unless there is some compiler optimization that creates such thing.

What if you try to replace capture with &, periodicalRetxFrom4 (to copy periodicalRetxFrom4, instead of taking reference). Would this make things better or worse?

The edit proposed in note-2 yields:

../tests/daemon/fw/best-route-strategy2.cpp:85:46: error: variable 'periodicalRetxFrom4' is uninitialized when used within its own initialization [-Werror,-Wuninitialized]
  function<void()> periodicalRetxFrom4 = [&, periodicalRetxFrom4] {
                   ~~~~~~~~~~~~~~~~~~~       ^~~~~~~~~~~~~~~~~~~
1 error generated.

I think scheduler should provide a periodical scheduling feature. It's useful for this test case and also #2056.

In fact, I think the error makes sense. Using capture-by-value as suggested is completely wrong here, you have to capture periodicalRetxFrom4 by reference, but with a small variation. Try this:

function<void()> periodicalRetxFrom4;
periodicalRetxFrom4 = [&] {
  ...
}