[gentoo-user] how to "git-bisect" in a portage-compatible way ?

[Nicolas Richard <theonewiththeevillook@yahoo.fr>]

Hello,

Background info : I'm experiencing a bug and found out that the bug
doesn't appear with libdrm-2.4.11 (I kept an ebuild for this one in
/usr/local/portage/...), but it does occur with libdrm-2.4.13 (not sure
about the version numbers anymore, and I have yet to try 2.4.12, too,
but that's not the question)

So the general question is : if I want to use git-bisect (I have never
done that before, but today is a good time to try), I guess it means
I'll have to build libdrm outside portage : if so, once I'm finished
with hunting the bug, how to go back to the situation where portage does
everything for me ?

Some more precise questions :
- before I begin, should I first unmerge libdrm ?
- once I finished with bisecting, should I reemerge libdrm ? Will
portage overwrite files it may need to overwrite ? what about orphanned
files (if any) ?

I looked at the documentation list on gentoo.org, I did find a section
entitled "Non-portage maintained software", but this is not what I'm
looking for. Where else should I look at ?

thanks for your comments

Nicolas.