hal-0.5.5.1-r1 installs README, CHANGELOG etc. in /usr/share/doc/hal-0.5.5.1-r1 and api, conf, spec in usr/share/doc/hal-0.5.5.1 Adding: --with-doc-dir=/usr/share/doc/${PF} \ to the econf in src_compile() put them all in /usr/share/doc/hal-0.5.5.1-r1 for me
fixed in hal-0.5.5.1-r2