[arch-general] can you only test certain packages?

[Jim Pryor]

On Thu, May 20, 2010 at 01:29:41PM -0400, Caleb Cushing wrote:
> I'm trying to help with the testing of perl 5.12 but I'd rather not
> test every package out there. Is it possible to block certain packages
> from being updated from testing? or only allow certain ones? maybe
> with a regex? obviously I don't wish to ban them globally. if they
> make it into a non testing repo I'm fine with it.

(This should be a sticky in the forum.)

There are exactly two safe options with respect to testing.

1. Update everything from testing. Actually this is a bit overkill. If
you just want to update a package Z, it'd be enough to update Z from
testing, and also any of its dependencies Y that are also in testing,
and also anything in testing that depends on either Z or any of the Ys.
That is, Z and all its dependencies, and everything for which any of
them are dependencies. Oh yeah, also any dependencies of any of those
items, and everything for which any of them are dependencies. And so on.
That might fall short of updating *everything* that's available for
update from testing. But it will often be many more packages than just
Z, and it will often be tedious to trace out all the packages that
should be included. So it'd be best to update everything from testing.

Sometimes it won't matter; you can just update Z and ignore other
available updates and nothing will go wrong. Other times it will matter.
So the only safe thing to do, going this way, is to update it all.
Especially if you want to *test* package Z, you should do it against its
intended environment.

2. The other safe option is to install *none* of the binary updates from
testing. Instead, grab the new PKGBUILD for Z from /var/abs/testing/,
and makepkg it yourself, against the other packages and libraries you've
already got installed. (If you can: that is, if Z doesn't require any
newer libraries that are only in testing.) This won't be an ideal test
environment for package Z, since it won't be the same binary environment
that Z will be deployed in. But for most purposes it should still be
pretty useful. And if you can successfully build and install Z, you
won't have to worry about library mismatches, like might happen if you
just installed the binary Z from testing without also installing
dependencies/dependents also in testing.

If you do go #2, you should also rebuild any packages that depend on
libraries installed by Z, and anything that depends on them, and so on.

-- 
Jim Pryor
profjim at jimpryor.net