[gentoo-user] question about portage capabilities

[Denis]

Hello all,

I am using a package called Rasmol, which is used for visualization of
molecular structures.  This software uses a certain table for atomic
sizes, and I need to change some values in that table - it is stored
in a header file within Rasmol source code.  There is an ebuild for
Rasmol, and it works fine - but what I'm wondering is how I can tell
portage to STOP once it unpacks Rasmol in the temporary work directory
- so I can tweak some things in the source code - and then resume the
build, using what's already in the work directory.  Looking at a
manpage for emerge, I didn't immediately get any creative ideas, but
might someone offer some advice for how to accomplish this?

Many thanks,
Denis