1369247 - The command run by |mach vendor rust| is sometimes not enough for updating dependencies

Status: RESOLVED DUPLICATE of bug 1361005

(Firefox Build System :: General, defect)

Description

[Xidorn Quan [:xidorn] UTC+10]

After updating rayon to 0.7.1 in Servo side in servo/servo#17105 (which is sync to autoland at [1]), |mach vendor rust| fails when it tries updating toolkit/library/rust/Cargo.lock, and the command it ran is
> cargo update --manifest-path toolkit/library/rust/Cargo.toml -p gkrust
which fails with the following message when I ran it manually:
>     Updating registry `https://github.com/rust-lang/crates.io-index`
> error: failed to select a version for `rayon` (required by `style`):
> all possible versions conflict with previously selected versions of `rayon`
>   version 0.7.0 in use by rayon v0.7.0
>   possible versions to select: 0.7.1

I have to run
> cargo update --manifest-path toolkit/library/rust/Cargo.toml -p rayon
> cargo update --manifest-path toolkit/library/gtest/rust/Cargo.toml -p rayon
to fix this issue.

It is not clear to me what's going on here. I found a Cargo issue rust-lang/cargo#782 which seems to be somehow related, but I failed to figure out any useful information from it.

I'm not sure whether it is something mach or cargo should handle.


[1] https://hg.mozilla.org/integration/autoland/rev/8905663e76c5d8ed9b17d4c6a679791f3f280d1f

Comment 1

[Alex Crichton [:acrichto]]

I wonder if this is similar to https://bugzilla.mozilla.org/show_bug.cgi?id=1361005?

Comment 2

[Xidorn Quan [:xidorn] UTC+10]

It might be a duplicate of that bug actually.

Could you provide more details about when would this happen? It doesn't seem to me this always happen. I mean, we have several dependency version bump, and they don't usually lead to this issue. I think there was a bindgen version bump, and vcs-sync ran the revendoring successfully at that time.

Comment 4

[Alex Crichton [:acrichto]]

This can typically happen when Cargo.lock/Cargo.toml are out of sync. In that situation a `cargo update -p gkrust` isn't guaranteed to succeed and the dependency graph may need a bit of massaging to get back into a resolvable state. This may also be a bug in `cargo update` depending on how you look at it, though.