Needing older library, but can't get emerge to install it

[Flake]

For building SNNS ( http://www-ra.informatik.uni-tuebingen.de/SNNS/) i need libm.so.5 , all other dependancies are met.

for all i know libm.so.5 is in one of the older glibc versions.

but when i try a emerge -p sys-libs/glibc-2.2.4-r9 i keep getting "not found or could be blocked by .."

it's not blocked in portage.mask, the ebuild script is there in front of my nose.

how do i get libm.so.5 on my system ???

or, for a beer, who can make a SNNS.ebuild for me?

(i would, but am still a little too green)

[lude]

[Flake]

it segfaults

or at least, it gives a "bus error"

[phosphan]