I attempted to emerge x11-misc/hsetroot, following the instructions on the Gentoo Wiki to install the FVWM-Crystal display manager. Build Log: http://bpaste.net/raw/187063/ Emerge --info: http://bpaste.net/raw/187074
Fixed in portage by using pkg-config to check x11 libs and then using them in src/Makefile.am for the linking of the hsetroot binary