crypto-common: note that 0.2.0 was [YANKED]

[dishmaker]

Resolves #2319

[shepmaster]

Note that I had asked why this crate was yanked, which this commit does not explain. As someone that is using crypto-common 0.2.0, I don't have any context to understand if I need to upgrade.

[newpavlov]

As mentioned in the changelog, v0.2.1 has introduced a breaking change. Technically we should've released v0.3.0, but since we thought that the impact will be minimal, we decided to sneak it in a patch release (see discussion in #2309).

if I need to upgrade

I think yanking of the version is a pretty clear signal that you should. But you may want to postpone the upgrade if you use existing pre-releases (e.g. see #2316) since the upgrade may break your builds.

[shepmaster]

As mentioned in the changelog, v0.2.1 has introduced a breaking change

I did not look at the rest of the changelog, only at this commit's diff, so I apologize. However, now that I do look at it, I don't think that the text in the changelog explains why 0.2.0 was yanked or clearly indicates what the breaking change in 0.2.1 would have been (or that it is a breaking change).

I already knew that the version was yanked as my builds / crates.io told me that already, so marking that version as "yanked" doesn't provide any information, other than it was an intentional yank and not a typo. What is missing is the why the yank happened. Having a dedicated sentence in the changelog along the lines of "this version was yanked because we forgot to make an important breaking change and decided to include that in 0.2.1" (or whatever phrasing is true and accurate), potentially with a link to the discussion you have above, would go a long way.

For what it's worth, in my changelogs, I include this with each relevant bullet point:

This is a **breaking change**.

I think yanking of the version is a pretty clear signal that you should.

Maybe for most people, but my interest arises because this crate has stopped the nightly playground builds from occurring. In the vast majority of cases that someone has yanked a version, it doesn't actually matter to the playground, but I can't tell that without some sort of documentation / explanation.

[newpavlov]

I will add a note for the yanked versions.

Maybe for most people, but my interest arises because this crate has stopped the nightly playground builds from occurring.

I wonder which crate is responsible for this:

error: failed to select a version for the requirement crypto-common = "=0.2.0"

Such bounds are notoriously fragile.

[newpavlov]

See #2325

[shepmaster]

I wonder which crate is responsible for this:

Oh, that's something I do specifically. I want to know when there are issues, but I also don't want to rebuild every crate every night.