the ebuild explicitly points to TCL_LIBDIR="/usr/$(get_libdir)/tcl8.5". Please do some more sofisticated checks for the tcl/tk version.
Created attachment 404320 [details]
and here it fails b/c just 8.4 is installed :
checking Tcl version... 8.6
checking Tk version... 8.6
checking for location of Tcl/Tk library... /usr/lib64/tcl8.5
configure: error: *** Tcl/Tk library directory /usr/lib64/tcl8.5 does not exist.
Closing as OBSOLETE - sci-geosciences/grass-7.0.1 has been added to the tree as per bug 514514 and subsequently revbumped. Note that sci-geosciences/grass:6 has been masked and will be removed from the tree in the coming weeks.