Git dependency with a path into a sub-folder location

[jnicholls]

For dependencies we can have git = <url> or path = <path> but we cannot combine the two, in the cases where a cargo package lives somewhere nested inside of a git repo, i.e. not in the root of the repo. It would be very powerful to be able to provide a relative path into a git repo.

Use case: A repo that is a client library containing bindings in more than one language, and the Rust binding is under the rust folder inside that repo.

The workaround today is to submodule the repo into your own repo, and use a relative path config. This levies the requirement of using git of course.

[alexcrichton]

You can actually do this today! When you depend on a git repository Cargo will crawl the entire repo looking for packages and you can depend on any of them.

[jnicholls]

Oh ok, awesome! I thought it failed the first time I tried it, but I'll give it another shot. Thanks.

[Terkwood]

Fantastic! This worked like a charm.

[augustoteixeira]

I tried this and it worked, but it gives me the following warning:

warning: dependency (ethcore-transaction) specification is ambiguous. Only one of `git` or `path` is allowed. This will be considered an error in future versions

I am using the following dependency:

ethcore-transaction = { git = "https://github.com/paritytech/parity-ethereum", path = "ethcore/transaction", branch = "master" }

With the following cargo version:

cargo 1.31.0 (339d9f9c8 2018-11-16)

Is it safe to keep this?

[alexcrichton]

@augustoteixeira you'll want to remove either git or path there, this'll become a hard error eventually

[augustoteixeira]

There is a huge git repo, from which I need a single folder (with its own cargo file and src folder).

What is the proper way to handle that?

[alexcrichton]

Unfortunately git has no way to check out only one folder, so there's nothing to do there unfortunately.

[augustoteixeira]

I see. So when I was doing this:

subfolder = { git = "url_for_the_big_repo", path = "subfolder" }

which leads to the warning. Cargo was just doing the same as if I had typed this?

subfolder = { git = "url_for_the_big_repo" }

[alexcrichton]

Correct!

[marcotuna]

Today I face the same issue, I was needing a sub folder inside a git repo. I think this should be implemented

[brenzi]

Isn't crawling the whole git repo dangerous? What happens if two different subfolders contain crates with equal name? Will that be reported? I would certainly favor allowing explicit subfolders with a combination of git = "....." path="....."

[ManevilleF]

What's the status of this? I'd like to use a git repo subfolder too

[askolesov]

Definitely need this feature. I encountered this today:

What happens if two different subfolders contain crates with equal name?

[sazzer]

Not only the issue of name clashes, but there's a performance cost to crawling a huge repo when the client can be told exactly where to look.

[flyq]

isn't crawling the whole git repo dangerous? What happens if two different subfolders contain crates with equal name? Will that be reported? I would certainly favor allowing explicit subfolders with a combination of git = "....." path="....."

I need it too, thanks google bring me here.

[wseaton]

There's an issue that can occur when there is a submodule inside of a repository, how do you explicitly depend on both the main folder and the sub-module without using path? Cargo automatically pulls the sub-module path into depends but the compiler doesn't like that.

Currently for one of my projects I have to do this to get cargo to properly pull the right versions and rust to compile:

[dependencies]
twitch_api2 = {git = "https://github.com/Emilgardis/twitch_api2", tag="v0.6.0-rc.1", features=["all"]}
twitch_oauth2 = { git = "https://github.com/Emilgardis/twitch_api2", tag="v0.6.0-rc.1", path="twitch_oauth2", features=["all"]}

Without this second line the compiler complains it can't find the crate, am I missing something?

 Compiling twitch_oauth2 v0.5.2 (https://github.com/Emilgardis/twitch_api2?tag=v0.6.0-rc.1#3b5f82ec)
   Compiling twitch_api2 v0.6.0-rc.1 (https://github.com/Emilgardis/twitch_api2?tag=v0.6.0-rc.1#3b5f82ec)
   Compiling twitch-dmenu v0.1.0 (/home/weaton/git/twitch-dmenu)
error[E0463]: can't find crate for `twitch_oauth2`
 --> src/main.rs:7:1
  |
7 | extern crate twitch_oauth2;
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ can't find crate

[kkartaltepe]

Still an issue especially when the submodules you dont want are hundreds of megabytes.

[Eh2406]

Yes, you are mistaken. If it is not working, please open a new issue with a minimal repoducabe example.

[kaimast]

Sorry... I resolved my issue and deleted the earlier post.

[TilakMaddy]

Hello, I am trying to load a subfolder in git as a dependency by doing this

config = { git = "https://github.com/foundry-rs/foundry", path = "crates" }

But I get the following error! @jnicholls Can you help me please?

error: failed to load manifest for workspace member `/Users/tilakmadichetti/Documents/OpenSource/realaderyn/aderyn`

Caused by:
  failed to load manifest for dependency `aderyn_driver`

Caused by:
  failed to parse manifest at `/Users/tilakmadichetti/Documents/OpenSource/realaderyn/aderyn_driver/Cargo.toml`

Caused by:
  dependency (config) specification is ambiguous. Only one of `git` or `path` is allowed.

[HALtheWise]

I came across an instance where the repo-searching behavior seems broken and I'm not sure how to resolve it correctly. Namely, https://github.com/cloudflare/workers-rs contains multiple crates, as well as a templates/ directory for cargo generate.

Because the templates have Cargo.toml files with incomplete data (i.e. template variables that need to be filled), Cargo emits tons of errors when it tries to scan them, even if it was never going to select them anyway.

[patch.crates-io]
worker = { git = "https://github.com/cloudflare/workers-rs.git", branch = "main" }

error: invalid character `{` in package name: `{{project-name}}`, the first character must be a Unicode XID start character (most letters or `_`)
 --> ../../home/esp/.cargo/git/checkouts/workers-rs-500ebb89f2186e75/9e1b665/templates/hello-world-http/Cargo.toml:2:8
  |
2 | name = "{{project-name}}"
  |        ^^^^^^^^^^^^^^^^^^
  |

[weihanglo]

@HALtheWise see #13724 for relevant discussions.