Feature request: rebuild documentation for old crates

[tspiteri]

When crates are not updated in a long time, their style starts to drift from the latest style (or the latest style drifts for them) and consequently they do not gain the latest rustdoc features. I think it would be nice if crates which were last updated one or two years ago are rerun and the docs updated with the latest rustdoc.

This could be low priority so that it does not slow down documentation of new crates.

If a compilation fails for whatever reason, of course the old version should be retained.

[jyn514]

Hmm I don't mind this idea but it seems expensive to rerun the build on all versions that have ever been published ... This would just affect style sheets and such, right? What should we do if building with a newer version of rustdoc leads to broken links?

[jyn514]

Related: #301

[jyn514]

#295 also mentioned allowing crate owners to re-queue builds for their own crates, e.g. if the build succeeds but the JavaScript throws a runtime error because of a bad nightly. However, this does not seem feasible at least from the website because we currently allow arbitrary JavaScript from built crates. See #301 (comment)