Switch from ld (the default linker) to using lld for GNU Linux targets

.cargo/config.toml

@@ -15,11 +15,18 @@ rustdocflags = ["-Znormalize-docs"]
 [target.x86_64-pc-windows-msvc]
 linker = "rust-lld"
 
-[target.aarch64-apple-darwin]
+[target.'cfg(target_os = "macos")']
 linker = "rust-lld"
 
-[target.x86_64-apple-darwin]
-linker = "rust-lld"
+[target.'cfg(all(target_os = "linux", target_env = "gnu"))']
+rustflags = [
+  "--cfg",
+  "tokio_unstable",
+  "-Zshare-generics=y",
+  "-Zthreads=8",
+  "-Csymbol-mangling-version=v0",
+  "-Clink-arg=-fuse-ld=lld",
+]
 
 [alias]
 xtask = "run --package xtask --"

.github/actions/setup-rust/action.yml

@@ -34,6 +34,11 @@ runs:
         # we want more specific settings
         cache: false
 
+    - name: "Install LLD (LLVM Linker) for Linux"
+      if: runner.os == 'Linux'
+      shell: bash
+      run: sudo apt-get -y update && sudo apt-get install -y lld
+
     - name: "Set Windows default host to MinGW"
       if: ${{ inputs.windows == 'true' }}
       shell: bash

CONTRIBUTING.md

@@ -29,6 +29,10 @@ Thanks for your interest in contributing to Turbo!
 - [Rust](https://www.rust-lang.org/tools/install)
 - [cargo-groups](https://github.com/nicholaslyang/cargo-groups) (used to group crates into Turborepo-specific ones and Turbopack-specific ones)
 
+### Linux Dependencies
+
+- LLD (LLVM Linker), as it's not installed by default on many Linux distributions (e.g. `apt install lld`).
+
 ## Contributing to Turborepo
 
 ### Building Turborepo