autoproj should run an osdeps operation before a build operation

[g-arjones]

If a package is selected for build and one of its dependencies is missing, autoproj will:

1. Checkout and build the missing dependency if that is a source package;
2. Do nothing if that is an osdep (the build will most likely fail in this case)

For a more consistent behavior, autoproj should perform an osdeps operation on the packages that are selected for build (this would be disabled by --no-deps/--deps=f).

[doudou]

I'm not necessarily against this, but only if it is disabled by default and can optionally be enabled.

The problem is that most osdeps are slow, so that would have a non-negligible impact on the build times. If you don't like the inconsistency, then I would simply make build fail even in the source package case, and ask to explicitely run an update.

[g-arjones]

only if it is disabled by default

I would be fine with that...

The problem is that most osdeps are slow

I guess there will be some impact on build times indeed.. I will do some testing to see how big they are, maybe it doesn't make sense to have this even as an optional feature.

I would simply make build fail even in the source package case

Not sure.. This is a major change in behavior IMO, I don't know how everyone else would feel about that