`libgit2-sys 0.13.3` version issue

[chenrui333]

It looks like the version scheme does not match what is specified in Cargo.toml

git2-rs/Cargo.toml

Line 23 in 9d33858

libgit2-sys = { path = "libgit2-sys", version = "0.13.3" }

This caused some build issue:

error: failed to select a version for the requirement `libgit2-sys = "^0.13.3"`
candidate versions found which didn't match: 0.13.2+1.4.2, 0.13.1+1.4.2, 0.13.0+1.4.1, ...
location searched: crates.io index
required by package `git2 v0.14.3`

[ehuss]

You'll need at least Rust 1.60.

@joshtriplett Perhaps we should yank the release and move #833 to the next semver release (0.14)?

[chenrui333]

noted about the rust 1.60.0
but i guess the semver issue might be still valid?

[joshtriplett]

@ehuss Just libgit2-sys, not git2? That probably wouldn't be too disruptive, since people don't tend to depend on libgit2-sys directly and use its types.

However, I'm not sure that'd actually solve the problem. Wouldn't Cargo still fail to find a matching libgit2-sys for 0.14 just as it does for 0.13.3?

[ehuss]

Nah, I think it would need to be both git2 and libgit2-sys.

Yanking isn't a full solution. If we make a new semver bump and a user tries to use git2 = "0.15" with an old rust version, it will run into the same issue.

This is one of the hazards of using this new syntax. My personal feeling is to wait at least a few months before switching to new stable things to reduce the likelihood of someone running into this kind of problem. But every project has its own guidelines.

[joshtriplett]

git2 0.14 was already rather disruptive; I'm hoping we don't need to move to a new semver-breaking version anytime soon.

I can see another possibility that would eliminate this particular issue: we could yank the latest git2 crate, and upload a new version of git2 that uses weak dependency syntax in git2's Cargo.toml as well (even though it isn't strictly needed). That would avoid the problem of people seeing the new git2 but not the new libgit2-sys; any Cargo capable of finding the new git2 would also find its dependencies.

[qrilka]

I get the same issue with the latest git2-0.14.4:

error: failed to select a version for the requirement `libgit2-sys = "^0.13.4"`
candidate versions found which didn't match: 0.13.2+1.4.2, 0.13.1+1.4.2, 0.13.0+1.4.1, ...
location searched: crates.io index
required by package `git2 v0.14.4`

Is there any workaround for this? I just can't build a test project after just adding git2 = "0.14.4" into [dependencies]

[qrilka]

looks like using 0.14.2 resolves this problem but cargo-outdated fails because it tries out the latest version...

[joshtriplett]

This issue manifests because libgit2-sys uses a new Cargo feature, so new versions of it aren't visible to old Cargo. While it won't help existing versions of Cargo, for future versions like this, ideally we should improve Cargo's handling of unknown versions, to detect if it encountered versions it didn't understand, and then report that you might want to upgrade Cargo. See rust-lang/cargo#10623 for discussion of that issue.