Description of problem: a2x -f pdf requires dblatex. Please add a Requirement on this package.
This was omitted intentionally[1] because not all asciidoc usecases require pdf support (such as html/manpage generation) and dblatex dependency chain is quite huge. What could possibly be done is a fedora-specific patch for a2x that would print some sane error message prompting to install dblatex (or rather latex subpackage). There is asciidoc-latex subpackage that pulls in dblatex and includes additional settings. [1] https://lists.fedoraproject.org/pipermail/devel/2013-March/179571.html
Thanks for the info. The patch is probably a good thing tho power-users might know what to do ..