fetchCargoVendor: support other registries

[jian-lin]

There is already a TODO item created by the author of fetchCargoVendor (@TomaSajt). This issue is to track its implementation.

My network connection to crates.io is not good. As a result, all my 6 attempts to build #377551 failed¹. If fetchCargoVendor supports other registries, I can use many fast mirrors of crates.io.

Footnotes

1. They were stuck at something like this forever: kanata> Fetching https://crates.io/api/v1/crates/windows-sys/0.52.0/download -> tarballs/windows-sys-0.52.0.tar.gz [1/0/3 built] building kanata-1.7.0-vendor-staging (buildPhase) ↩

[TomaSajt]

IIUIC you're saying that you want to fetch all crates-io sources from a different download link.

Note, that this is not exactly the same as the TODO comment, which is about the case where the lockfile itself is using a different registry.

Before fetchCargoVendor I'm assuming you still had the same connectivity issues.

Could you provide examples with fetchCargoTarball and importCargoLock? (assuming they support it)

[jian-lin]

I put this in the ~/.cargo/config.toml file.

[source.crates-io]
replace-with = "a-fast-mirror"

[source.a-fast-mirror]
registry = "sparse+https://mirror.example.com/crates.io-index/"

Then cargo build outside of nix will fetch things from a-fast-mirror.

Honestly, I am not sure if fetchCargoTarball support this. I did not notice network connection issue before and I do change my ISP recently.

edit: I have no issue with fetchCargoTarball because it supports proxy but fetchCargoVendor does not.

[jian-lin]

Honestly, I am not sure if fetchCargoTarball support this.

It is supported by fetchCargoTarball using NIX_CRATES_INDEX.