Please rekeyword =net-irc/weechat-1.6 and its new dep for building docs, dev-ruby/asciidoctor (and its long tail of ruby bdeps/test deps).
net-irc/weechat-1.7-r1 works fine for me on ARM.
Closing as obsolete since 1.9 is now stabilized in the tree. Please open a new bug if you want other arches keyworded.