unable to update a dependency using sparse protocol

[jakecoffman]

Problem

Hello from the Dependabot team 👋

We recently updated to Rust 1.68.2 and enabled the sparse registry environment variable but we're seeing this error when running updates: usage of sparse registries requires `-Z sparse-registry` .

The blog post doesn't mention needing to set that, and when I do I get: error: the `-Z` flag is only accepted on the nightly channel of Cargo, but this is the `stable` channel so this seems like it might be a bug?

Steps

export CARGO_REGISTRIES_CRATES_IO_PROTOCOL=sparse
git clone --depth=1 https://github.com/geo-engine/geoengine
cd geoengine
cargo update -p time --verbose

Possible Solution(s)

No response

Notes

No response

Version

On my Mac where I can reproduce it:

cargo 1.68.0-nightly (2381cbdb4 2022-12-23)
release: 1.68.0-nightly
commit-hash: 2381cbdb4e9b07090f552d34a44a529b6e620e44
commit-date: 2022-12-23
host: aarch64-apple-darwin
libgit2: 1.5.0 (sys:0.15.0 vendored)
libcurl: 7.87.0 (sys:0.4.59+curl-7.86.0 system ssl:(SecureTransport) LibreSSL/3.3.6)
os: Mac OS 13.3.1 [64-bit]

But you can see what Dependabot is running here.

[weihanglo]

The stabilization was done and synced up to rust-lang/rust on Jan 20th (rust-lang/rust#107120). Before that the feature was still unstable, and geoengine seems to pin on nightly-2022-12-28 with their rust-toolchain file.

[jakecoffman]

Ah ok, we'll have to be a bit smarter about the older toolchains then. Thanks for the info!