[Pkg-rust-maintainers] Bug#913408: Bug#901827: dpkg: Support two-sided version constraint ranges, required to properly translate Cargo dependencies

[Guillem Jover]

Control: severity 901827 wishlist

On Sat, 2018-11-10 at 23:16:00 +0000, Ximin Luo wrote:
> This translation scheme works for Depends and Build-Depends, however
> it does not work for Replaces and Breaks, please see #913408 for an
> example of the problem.
> 
> In the abstract example above, since A-5 (= 5.1.1) replaces files
> from a previously-uploaded A (= 5.1.1), it must declare
> Replaces+Breaks: A (= 5). But in reality, there may be multiple
> Debian uploads of 5.1.1 including security uploads and backports.
> So we really need to declare:
> 
> Breaks: A (>= 5.1.1~~, << 5.1.2~~)
> Replaces: A (>= 5.1.1~~, << 5.1.2~~)
> 
> but this is not possible in Debian today. Note that this:
> 
> Breaks: A (>= 5.1.1~~), A (<< 5.1.2~~)
> Replaces: A (>= 5.1.1~~), A (<< 5.1.2~~)
> 
> won't work as it is equivalent to Breaks: A, Replaces: A which is not
> what we want.

As has been mentioned elsewhere, I don't think we really need to do
this strict range coverage, because in general we do not support
downgrades, and only upgrading forward.

In any case, this is still a whishlist bug, reset accordingly.

Thanks,
Guillem