Comment 6 for bug 1597594

Thanks for the explanation Thomas.
I can confirm that the default branch does now build OK on Fedora 24.

Here, optional headers not found

-- Could not find OPTIONAL package Optional
-- No optional headers found, fall back to boost
-- Boost version: 1.60.0

which is probably of little consequence since it builds, but just to improve my (lack of) understanding on this, are the optional headers being searched for not the ones provided by Boost-devel on Fedora 24, or is cmake just not finding them here?

Cheers,
Terry