RFE: deprecation metadata

[Robert P. Goldman]

In discussions with Peter S/gigamonkey last night, we were discussing what to do about libraries that have become obsolete. E.g., I believe that XMLS is now obsolete and CXML should be used instead, the latter being backward compatible with the former and more capable.

Peter suggested adding a :deprecated metadata item to DEFSYSTEM.

I'd suggest that this metadata item be string-valued, so that the programmer can provide an explanation of the deprecation (ideally including suggestions for how to replace the deprecated system). When ASDF loads a system with non-null deprecation, it could print a warning, incorporating the deprecated item metadata.

I believe that this could be done without issues of backward compatibility, since ASDF is permissive about parsing defsystem options.

[Faré (fahree)]

Sounds good to me, but make sure to test it on an old ASDF before you commit.

[Robert P. Goldman (rpgoldman)]

Sigh. You were right. DEFSYSTEM is not permissive. :-(

[Faré (fahree)]

Well, that doesn't mean you can't add the keyword.
But it does mean that those who use it should implicitly or explicitly
:defsystem-depends-on ((:version :asdf "2.010"))

Should we rename our current 2.140+ branch to 2.010.1 ?
Or at some point start using 2.200 and 2.200.1 instead of 2.200 and 2.300 ?
Or converge towards the second Feigenbaum constant?

[Robert P. Goldman (rpgoldman)]

On 10/22/10 Oct 22 -10:47 PM, Faré wrote:
> Well, that doesn't mean you can't add the keyword.
> But it does mean that those who use it should implicitly or explicitly
> :defsystem-depends-on ((:version :asdf "2.010"))

This led me to https://bugs.launchpad.net/asdf/+bug/665724

I will move the remainder of this discussion to that ticket...