* Andrey Rahmatullin <wrar@debian.org>, 2014-10-04, 17:29:
You don't need debian/tmp/ prefixes in .manpages.
You do need them. dh_installman doesn't look into debian/tmp; only dh_install does.
That said, if the upstream build system puts the manpages in the correct location (which apparently is the case here), you probably shouldn't use *.manpages at all, but add the manpages to *.install instead.
-- Jakub Wilk