rkhunter has within its tests invocation of lsof with `M` parameter (simply grep script boby for LSOF_CMD). This option is only available when lsof is built with rpc support which is enabled via `rpc` USE flag. Therefore rkhunter should depend on lsof[rpc] otherwise it will fail to run some tests with a warning from lsof about incorrect parameters.
+ 11 Apr 2013; Patrick Lauer <email@example.com> rkhunter-1.4.0.ebuild:
+ Dependency fix for #447078