[gentoo-portage-dev] Passing CFLAGS="-fdebug-prefix-map=..=$(readlink -f ..)"

[Joakim Tjernlund]

I am trying to add -fdebug-prefix-map to my CFLAGS but cannot get past 
"$(readlink -f ..)"
Portage will not expand $(anything)

Any way to make portage expand "$(readlink -f ..)" ?

 Jocke