Protect specific TexLive directory from updates?

[ibrunton]

I'm using the current TexLive (2012) and biber/biblatex. However, I need a more recent version of the biblatex-mla package. I'm able to clone its git repository in my home directory and symlink to it from /usr/share/texmf-dist/tex/latex/, but obviously the next time TexLive gets updated, that will get overwritten. Is there a way to tell portage/emerge to ignore that symlink?

Alternatively, is there a place I can put the git repo or a config setting to tell latex and biber to prefer the git repo over the one in /usr/share ? Right now it's in ~/.texmf but without that symlink it doesn't get sourced.
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