So, I'm supposed to be starting a blog, and (for reasons to be
discussed later) I want to have it up by 6 o'clock (5 o'clock central,
where I'm writing this) this morning.  It really ought to live
somewhere on kaduk.org, but (1) I haven't figured out where, yet,
and (2) for logistical reasons too boring to go into here, that domain
isn't serving anything at the moment.  So, a text file will suffice
for now, and I'll try to backfill it in to what I do finally end up with.

Anyway, ...

My first FreeBSD package (part 1)

In a long chain of yaks, I find that I need a copy of libss.so on
my system.  (For, you see, I want to use barnowl with zephyr locally
instead of remotely, and zephyr's zctl requires libss....)
I could just install heimdal (or KTH krb4, but that's marked as
BROKEN for recent versions), but that's kind of a huge package
and can cause excitement by conflicting with the hacked-up version
of heimdal that's in the base system.  Alternately, I could grab
the source from e2fsprogs and build its copy of libss, and get
just what I need.  So began an adventure ...

Luckily, there is a lot of good documentation --- one of the great
things about FreeBSD is that there's pretty good documentation
for most of the things you might want to do, and most of it is
even not horrendously outdated.  Here, my first step was to consult
the Porter's Handbook:
http://www.freebsd.org/doc/en/books/porters-handbook/index.html
Unfortunately, "Quick Porting" was not for me, as I wanted to
fetch a medium-sized distfile (e2fsprogs) and only build a small
part of it.  So I got to read through most of the book.
At the time, I was only looking for how to get this one particular
package to work, so I could skip a lot.  But the rest of it
is useful reading in general, and I would pick up on it later.

The first step in building a package is to get the source code;
in this case, that actually took some thought, since the name of
the tarball (a.k.a. "distfile") that I want bears basically
no relation to what I thought I was going to call the port (libss).
The file I want is e2fsprogs_1.41.9.orig.tar.gz (e2fsprogs
is a Debian package (maintained by tytso@mit.edu !), so there's
a '.orig' in there), and it's hosted on any Debian mirror.
The core of a FreeBSD port is a Makefile, so to tell the system
where to find the source code, I only had to specify a few make(1)
variables:
MASTER_SITES=   ${MASTER_SITE_DEBIAN}
MASTER_SITE_SUBDIR=     pool/main/e/e2fsprogs
DISTFILES=      e2fsprogs_1.41.9.orig.tar.gz
.include <bsd.port.mk>
Note that MASTER_SITE_DEBIAN is defined by the infrastructure,
so I automatically get the full set of Debian mirrors.
There's a patch release of e2fsprogs out, though, so I might
as well grab that, too, as an extra set of patches:
PATCH_SITES=    http://ftp.debian.org/debian/pool/main/e/e2fsprogs/
PATCHFILES=     e2fsprogs_1.41.9-1.diff.gz
PATCH_DIST_STRIP=       -p1
(and strip git's 'a/' and 'b/' from the patch.)

Now that I have the source, I let the port infrasructure gunzip(1)
and un-tar(1) the file (a.k.a. "extract" it), and I have to specify
where it extracts to (but only because Debian put that '.orig' in
there ...):
WRKSRC=         ${WRKDIR}/e2fsprogs-1.41.9
Unfortunately, most of the preceding code is Wrong, and though my
first attempt worked (that is, it installed a libss.so.2 that
I could link against), it was not up to the style standards
expected of a FreeBSD port, and I had to rewrite most of it.

It turns out that since I only want to install a small part
of some other piece of software, I can leverage a bunch of
the "master" port's code and write a smaller "slave" port,
that will track the updates of the "master" port.  Thus:
MASTERDIR=      ${.CURDIR}/../../sysutils/e2fsprogs
.include "${MASTERDIR}/Makefile"
The '.include' of either the master ports' Makefile or bsd.port.mk
should occur at the end of the Makefile --- I'm moving things around
a bit to show how my Makefile grew, and will post the full final
Makefile later.
Anyway, the master port's Makefile sets WKRSRC for me, and
does all the work to fetch and extract a reasonably-current
distfile for e2fsprogs.  Less work for me!

What to do once I've got a working directory with extracted
source in it is the subject of a later entry.