## orig tarball generation ##

Upstream does not include rules in SpamAssassin releases.  Rules are
only provided in the SpamAssassin trunk branch.  We previously used
dpkg source components, as documented in dpkg-source(1) to re-merge
the separate upstream components.  More recently, we have switched to
generating a single unified orig tarball from upstream svn.  The
primary component of the orig tarball is the content of a svn release
tag.  In addition to that, the 'rules', 'rulesrc', and 't.rules'
subdirectories from trunk are included.  The debian/bin/genorig.pl
script can be useful for generating these tarballs.  This script
determines the upstream release based on the most recent entry in
debian/changelog and generates a corresponding orig file.  Note, of
course, that once a tarball for a given upstream release is in the
Debian archive, it should not need to be regenerated.

## Working tree management ##

Spamassassin packaging borrows some useful targets in debian/rules from
the Debian kernel packaging project.  These targets are useful to manage a
debianized working directory for the entire source package when only the
debian/ subdirectory is actually tracked in git.  To get started working
on spamassassin, run:

$ ./debian/rules orig

The .orig.tar.xz and .pkgrules-orig.tar.xz files corresponding to the
current upstream release should be present in ../orig.  These files will
be unpacked and overlaid on top of the current working directory.  From
that directory, changes to upstream files can be developed using quilt.

To remove the upstream content, run:

$ fakeroot ./debian/rules maintainerclean

## packaging a new upstream release ##

1. On the appropriate Debian branch (e.g. experimental or master),
   update debian/changelog to add an entry corresponding with the
   version being packaged.  The genorig.pl script described above will
   determine which upstream components to checkout, and from where to
   check them out, based on the version in debian/changelog.

2. Generate the orig.tar.xz using ./debian/bin/genorig.pl

3. Import the orig tarball into the upstream and pristine-tar branches
   using gbp import-orig, e.g.
   gbp import-orig --pristine-tar \
   --no-merge --debian-branch=experimental \
   ../spamassassin_4.0.0~0.0svn1894153.orig.tar.xz

4. Update the working tree and build, e.g.
   make -f debian/rules orig
   dpkg-buildpackage

 -- Noah Meyerhans <noahm@debian.org>, Tue, 12 Oct 2021 09:56:55 -0700