Handle source replacement separately for [dependencies] and [dev-dependencies]

[mssun]

Describe the problem you are trying to solve

I understand that cargo has a feature to replace dependency source to self-hosted: https://doc.rust-lang.org/cargo/reference/source-replacement.html

However, it seems that I cannot do source replacement of source.crates-io only for [dependencies] but not for [build-dependencies]?

Describe the solution you'd like

Handle source replacement separately like this:

[source.dependencies.crates-io]
replace-with = "my-vendor-source-for-build-deps"

[source.dev-dependencies.crates-io]
replace-with = "my-vendor-source-for-dev-deps"

Notes

This issue has been discussed here: https://users.rust-lang.org/t/source-replacement-for-dependencies-only-but-not-for-build-dependencies/35411

[epage]

The problem is that dependencies and dev-dependencies are both for the target platform, so they can't be split. However, build-dependencies are for the host platform and I could see doing a split there.

Based on the users thread, I think that is more of what was intended

I'm targeting a special platform, so we maintain a set of modified crates which is only for that platform (GitHub - mesalock-linux/crates-sgx). However, this is not for building environment (i.e., build dependencies). So we still want to use crates on crates-io for build dependencies. That's the use-case when we want to distinguish dependencies and bulid-dependencies. Thanks!

If a crate is used both by [dependencies] and [build-dependencies], we cannot replace only for [dependencies].