Override a Cargo dependency by adding a [patch] section to Cargo.toml pointing to a local path or alternative source.
Add a [patch] section to your Cargo.toml to replace a dependency with a local path or a different registry source.
[patch.crates-io]
serde = { path = "../my-serde" }
This tells Cargo to use the serde crate from the specified local path instead of the version published on crates.io.
The [patch] section in Cargo.toml lets you swap out a standard library dependency for your own custom version. You use this when you need to test a fix or a new feature in a dependency before it is officially released. Think of it like swapping a pre-made car part with a custom one you built in your garage to see if it works better.