Re: rust-team branch merged

[Jason Conroy <jconroy@tscripta.net>]

Efraim Flashner <efraim@flashner.co.il> writes:

> Currently if you were to pull in rust-rand-0.8 and rust-rand-0.7 
> then
> you'd have both rand-0.*.crate files in the registry but only 
> one of
> them would be listed in share/cargo/registry/index/ra/nd/rand. I 
> need to
> adjust the generation of that file to combine multiple sources 
> if they
> exist, and sort them (I'm not sure it's necessary, but wouldn't 
> be
> surprised if we hit undefined behaviour if they were listed 
> multiple
> times or out of order).

Hi Efraim,

I'm currently investigating this limitation of your proposed 
patch.

Did you have a strategy in mind for how to fix it? I see that the 
index files are currently generated during a phase of 
cargo-build-system, rather than as a profile hook. So, to build an 
index that properly reflects the contents of a profile, it would 
seem that the two simplest options are: a) keep your existing 
index-generation logic during the build, and merge these 
per-package index files when building the profile; or b) move your 
patch's index-generating code out of the build phase and into a 
profile hook, so that we build each index file in a single pass 
(for all versions of a package) rather than merging the files from 
each package output.

On the surface option (b) seems cleaner, but maybe you had a 
reason for generating the index contents during the build?

Jason