Open Source Ecosystems

Patch-Crate

patch-crate lets rust app developer instantly make and keep fixes to rust crate dependencies. It's a vital band-aid for those of us living on the bleeding edge.

# fix a bug in one of your dependencies
vim target/patch/brokencrate

# run patch-crate to create a .patch file
cargo patch-crate some-crate

# commit the patch file to share the fix with your team
git add patches/some-crate+3.14.15.patch
git commit -m "fix broken_file.rs in some-crate"

Checkout our example at here.

Get started

Install command patch-crate
```
cargo install patch-crate
```

Add broken crate in your Cargo.toml


[package.metadata.patch]
crates = ["some-crate"]

[patch.crates-io]
some-crate = { path="./target/patch/some-crate-1.0.110" }

Download the crate's source code into target/patch
```
cargo patch-crate
```
Fix the broken code in target/patch/some-crate directly.
Create a crate-patch
```
cargo patch-crate some-crate
```

Commit the patch file to share the fix with your team

git add patches/some-crate+1.0.110.patch
git commit -m "fix broken-code in some-crate"

Instead of running cargo patch-crate its also possible to add a build.rs file like this:
```
fn main() {
   println!("cargo:rerun-if-changed=Cargo.toml");
   patch_crate::run().expect("Failed while patching");
}
```
To make it work, add the patch-crate library to the build-dependencies
```
patch-crate = "0.1"
```

Command explanation

cargo patch-crate

Apply patch files in ./patches to ./target/patch/crate-xxx if it not exist.
cargo patch-crate --force

Clean up ./target/patch/ and apply patch files in ./patches to ./target/patch/crate-xxx.
crate patch-crate <crate name1> <crate name2> ...

Create patch file of specific crate from ./target/patch/crate-xxx and save to ./patches