the generated tarball is not yet available on sourceforge

Meanwhile It's available.
Due to various reasons there is some delay until it's uploaded to SF and some more delay until it's replicated to all SF servers.

I am currently considering building the package directly from the auto-generated source tarball

Keep in mind there is not only the missing documentation, but also the missing 3rd party components installed by composer.

@dvzrv
I'm aware of the obsolescence of Publican, but switching the to a new toolchain and/or format is no small undertaking, and as much as I would like to do it, the conversion effort is unfortunately too great at the moment for the time I am able to invest in MantisBT.

I also failed to find Publican binaries after fedorahosted.org was killed, and even reported the issue but never got any response.

As for not being able to download the release tarballs from SourceForge, as an alternative you can always get the nightly build following the release from our own server (https://mantisbt.org/builds.php).

The latest version of the documentation is also available online in different versions including downloadable for offline viewing.

@atrol: Yes, the missing 3rdparty components should be no problem though, as we can use composer to install them in the packaging process.

@dregad: I understand. Do you currently use a Fedora system to generate the docs? Maybe there is an easy alternative solution to publican.
If I come across one, I'll post it here!