Cross-compilation instructions

Cross.toml

@@ -0,0 +1,2 @@
+[target.x86_64-unknown-linux-gnu]
+image = "ghcr.io/cross-rs/x86_64-unknown-linux-gnu:main"

README.md

@@ -115,6 +115,28 @@ cargo fmt
 cargo clippy
 ```
 
+## Cross-Compilation
+
+To build a Linux x86_64 binary from macOS:
+
+1. Install [cargo-zigbuild](https://github.com/rust-cross/cargo-zigbuild) and [Zig](https://ziglang.org/):
+   ```bash
+   cargo install cargo-zigbuild
+   brew install zig
+   ```
+
+2. Add the Linux target:
+   ```bash
+   rustup target add x86_64-unknown-linux-gnu
+   ```
+
+3. Build:
+   ```bash
+   cargo zigbuild --release --target x86_64-unknown-linux-gnu
+   ```
+
+The binary will be at `target/x86_64-unknown-linux-gnu/release/log_ingest`.
+
 ## License
 
 MIT