Plan to help migration to the new pkgdb location - RFC

[David Brownlee <abs%absd.org@localhost>]

We've moved to a new pkgdb location, but there are a number of
pitfalls in migration, which is hitting people on pkgsrc-current now,
and likely to hit a lot more come the next branch.

There is information on the pkgsrc mailing lists which should be
sufficient for technical users, but it would be helpful if we could
provide something for users for whom the first indication would be
updating pkgin or running a periodic update of pkgsrc current on
anoncvs.

Apologies for coming late to the show, but I think that pulling some
of the existing suggestions together we can make things substantially
easier for a lot of users.

As I see it we have two key issues:
1) The potential split brain from having two pkgdbs, and mixing tool versions
2) No easy migration (at the "run one command" level)

and two affected areas - users using pkgsrc to build, and those using pkgin.

Taking pkgsrc first:

I think the tools when run with a default /usr/pkg on NetBSD < 10
should check for the existence of /var/db/pkg present as a non symlink
and error out with instructions to either:

a) touch a file (/var/db/pkg/.bypasscheck?), which the tools then take
as a "just shut up and work. We should also have a pkgsrc variable for
edge cases

b) mv the files across to /usr/pkg/ and symlink (the key point is this
make makes any old /usr/sbin/ pkg_install safe to use as well)

Ideally this should be wrapped up in a single shell command which runs
any additional safety checks - eg:
- pkgsrc/tools/pkg_install/pkgdb-check ignore
or
- pkgsrc/tools/pkg_install/pkgdb-check migrate

So the advice on the lists is "if you're not doing anything special,
update pkgsrc and run "pkgsrc/tools/pkg_install/pkgdb-check migrate".
If you have a special setup (multiple installed pkgsrc versions,
custom pkgdb paths etc, run "pkgsrc/tools/pkg_install/pkgdb-check
ignore" once.

Its *possible* that it may make sense to build the checks into
pkg_install itself, which would also help pkgin.


What do people think?

David