How to best write a patch/upgrade to a Gentoo program?

[Cuardin]

This question has probably been brought up before, but with all the emerging problems discussed I couldn't weed it out, so here goes.

I am not happy with one of the programs written by the Gentoo team, and I wish to add functionality to it. Which program it is is not the issue. What I gather, my options are either to get a CVS account, or extract the source from the speciffic euild package and edit or write a patch directly.

However, I am not comfortable with CVS, and as I understand it editing the source tarballs will change their md5 sums and protage will complain. Finally, the changes I want to make are a little to substantial to just write a patch off the top of my head.

Considdering the aim of Linux, and especially Gentoo, I had expected there to be a howto on this, but I havn't found it yet.

Hope someone can help me out here.
--Daniel Armyr

[Sven Vermeulen]

Get the sources. You will probably find those in /usr/portage/distfiles. If you want to know what the sources are called, issue "emerge -fp <tool>".

Unpack the sources, make your adjustements, make a patch against the original sources of your modified sources. Now edit the ebuild-file (don't forget to change the number, f.i. add a -r1 or similar) and make sure the patch is issued automatically. Add the patch to the files/ directory where the ebuild is located. Issue "ebuild /path/to/ebuild merge" and hope for the best.

Also, there are developer docs on how to create or edit ebuilds. Do read them. It isn't difficult, but it requires a little thought

[Cuardin]

Thanks. I'll give it a go.
--Daniel Armyr