Not clear how to [patch] sources other than crates-io

[frankier]

So I think this might be a documentation bug rather than anything else. On the page: http://doc.crates.io/manifest.html#the-patch-section

Each key after [patch] is a URL of the source that's being patched, or crates-io if you're modifying the https://crates.io registry. In the example above crates-io could be replaced with a git URL such as https://github.com/rust-lang-nursery/log.

So after reading this, there are two thing you might try. If you're not that familiar with toml, then you might try the following:

[patch.https://github.com/rust-lang-nursery/log]
...

This is not valid toml. Another thing you might try is

[patch]
"https://github.com/rust-lang-nursery/log" = { log = { path = "/path/to/log/" } }

But this is ignored ("warning: unused manifest key: patch")

Ideally there would be a working example in the docs.

[elidupree]

I was able to get this feature working by putting the URL in quotes:

[dependencies]
codecophony = {git = "https://github.com/elidupree/codecophony.git"}

...

[patch."https://github.com/elidupree/codecophony.git"]
codecophony = {path="/n/codecophony-share-build/codecophony"}

[Ericson2314]

With something like rust-lang/rfcs#1133 on the horizon, we will also have standard library deps. Eventually Cargo and the provided compiler will somehow negotiate to get Cargo any compiler-specific sources for standard library crates. But, figuring that out will involve many people and grind things to a halt. So the stop-gap solution in rust-lang/rfcs#1133 was to allow the user to [patch]-in standard library deps so that users can continue without this.

tl;dr, need to [patch] standard library deps.

[alexcrichton]

I believe this was since documented, so closing.

[Ericson2314]

https://doc.rust-lang.org/cargo/reference/manifest.html#the-patch-section doesn't yet contain this?

[sjackman]

Patching dependencies does not work if it's for the same location but a different branch

See #5478