I've just looked into it, and it seems that the bash-completions expect _argcomplete function to be declared -- yet it is nowhere to be found. Supposedly you are supposed to use register-python-argcomplete to obtain the completions, i.e.: register-python-argcomplete > "${T}"/${PN} dobashcomp "${T}"/${PN} (IOW, the bundled completion is useless, and you install it with wrong name)
+ 26 Jun 2015; Justin Lecher <jlec@gentoo.org> -linkchecker-9.2.ebuild, + metadata.xml: + Cleaned old; obsoletes bug #508314 and bug #521336 +