Creating a derivate work, asking for a licence "linking exception"

[stefan at li-ch.com]

Hi

I'm writing a java library which intends to be able interact with a
mercurial repository. While the ultimate goal would be to be full-fledged,
a more immediate goal is to be able to read revlogs, changelog and
dirstate.

To do this I have looked at the mercurial source which makes my work a
derivate work (sort of equivalent of translating).

This project of mine started as an attempt to speed up the "hg status" for
files in the Mercrual Eclipse Plugin. While it has a long way to go, I
have come further than I expected.

This is most probably a derivate work and as I understand it since hg is
GPL my work has to be GPL. And as such, my java library cannot be included
into the eclipse plugin without having some sort of "linking" exception
such as the classpath exception.

I understand that FSF sometimes grants exceptions
   See bullet 10) at http://www.opensource.org/licenses/gpl-2.0.php

Therefore I ask who could (even if s/he doesn't wan't to :-)) grant me
such and exception? (ie, who owns the licence). And if so, under what
conditions?
I'd be happy to make my derivate work GPL with an classpath exception or
similar, protecting your and my work while maintaining linking possible.

The following files I have currently studied

   revlog.py, mdiff.py, mpatch.c

and the corresponding wiki content of developerinfo
with addition of the DirState, Manifest and ChangeLog

It is likely I have to look at more :/

Thank you

Stefan Chyssler