[gentoo-user] Selecting a particular svn version to emerge on 9999 ebuilds

[Mick]

Hi All,

I am trying to troubleshoot e17 which on one laptop recently started shutting 
down the monitor backlight when the WM starts.  I can't recover from it, 
Ctrl+Alt+F1 is also showing a black screen, stopping X does not fix it and the 
only solution is to shutdown again.  Thankfully I use startx so I can always 
boot back into a console.  <phew!>

I want to find out which version this started happening from, but with portage  
9999 ebuilds I am not sure how to specify which version I want all the e17 
packages to download and install from svn.

Is there a particular incantation?  There's a number of packages and therefore 
I would rather not have to manually modify umpteen ebuilds a number of times 
to do this (which is what I recall I had to do with a wireless driver ebuild 
in the past).

I tried:

ESVN_OPTIONS="-r64511" emerge <blah-blah> but it did not work.
-- 
Regards,
Mick