[asdf-devel] The issue at hand

[Pascal Costanza]

> The new ASDF will break systems that subclass OPERATION.  Those
> libraries' maintainers will have to look at their code, based on the
> error message, and see what needs to be done.  For the vast majority of
> them, five minutes work will suffice.  For those that take more... well,
> as you point out, the bug fix had to be made, and I stand ready to help
> those who need assistance adjusting.

It's good to signal an error or a warning for this case.

It would have been better if asdf:operation would have kept its old semantics, maybe with a deprecation warning when it's used, and that the new semantics would have been provided by, say, asdf3:operation. People who see the warning and care about keeping things up to date could react to the warning and move from asdf:operation to asdf3:operation, which is not much more work than what is necessary now. People who care less (maybe because other things are more important - asdf is not the center of the universe after all) would not need worry, because everything would work as before, even in a setting where both asdf2 and asdf3 semantics would be needed side by side.

Pascal