Re: SEUL: Migration, and a brief recap

[Erik Walthinsen <omega@omegacs.net>]

> No, no, no, you don't understand the way this works.  There's no such
> thing as changing package managers, all we can do is start over from the
> beginning and throw out what we've done.  All we can do is a total
> rewrite.  The installer calls rpmlib functions internally, trying to gut
> these would be next to impossible.  We start with RPM, we stay with it.
> No changing.  Remember, guys, this is a ONE WAY trip.

Not so.  An RPM is built from sources and a SPEC file.  The entire point of 
RPM is to maintain pristine sources, so if you lose the primary archive, you 
just go find it again at the original site.  Patches are then applied to 
bring the software into compliance with whatever distribution.  These 
patches, plus the pristine sources (if it's legal, not the case with pgp, 
etc.), form the SRPM.

To convert a package from, say, RPM to DPKG, you do the following:

1) unpack the SRPM: `rpm -Uvh package-1.0-1.src.rpm`
2) look at the spec file: `cd /usr/src/redhat/SPECS;less package-1.0-1.spec`
3) convert this spec file into DPKG's equivalent
4) move the source and spec files into a DPKG-compatible build tree
5) build the DPKG from the sources.

I'm assuming above that DPKG is similar to RPM as far as its build 
environment goes.  I don't know very much about the developer environment for 
DPKG, and I would really like it if someone would write up a white paper on 
the differences.

Assuming the above, it would probably take one person on volunteer time a 
week or two to convert an entire RedHat-sized distribution.


> And, as things stand RIGHT NOW, RPM is the better candidate.

Agreed.

     Erik Walthinsen <omega@seul.org> - SEUL Project system architect
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       /  \                SEUL: Simple End-User Linux -
      |    | M E G A            Creating a Linux distribution
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