From ad2eec3fdebdbf60ca28e7825699bd55071a2338 Mon Sep 17 00:00:00 2001
From: James Kay <james.kay@linera.io>
Date: Thu, 16 Nov 2023 16:34:51 +0000
Subject: [PATCH] Codify linting toolchain in a toolchain file

Moves the nightly toolchain we use for linting out of a GitHub action
and into a dedicated `rust-toolchain.lint.toml` file.

rustup doesn't currently support specifying a toolchain file, though
[it will soon](https://github.com/rust-lang/rustup/issues/2686), so we
hack around it by moving the toolchain file back and forth as part of
the GitHub action for Rust.
---
 .github/workflows/rust.yml           | 8 ++++----
 rust-toolchain.toml                  | 6 +-----
 toolchains/build/rust-toolchain.toml | 5 +++++
 toolchains/lint/rust-toolchain.toml  | 4 ++++
 4 files changed, 14 insertions(+), 9 deletions(-)
 mode change 100644 => 120000 rust-toolchain.toml
 create mode 100644 toolchains/build/rust-toolchain.toml
 create mode 100644 toolchains/lint/rust-toolchain.toml

diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 5481ec7a7bc..ddb0eb1dd81 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -102,11 +102,11 @@ jobs:
       run: >
         find linera-* -name '*.rs' -a -not -wholename '*/target/*' -print0
         | xargs -0 -L1 ./scripts/target/release/check_copyright_header
+    - name: Put lint toolchain file in place
+      run: |
+        ln -sf rust-toolchain.lint.toml rust-toolchain.toml
     - uses: Twey/setup-rust-toolchain@v1
-      with:
-        toolchain: nightly-2023-10-22
-        target: wasm32-unknown-unknown
-        components: clippy rustfmt
+      working-directory: toolchains/lint
     - name: Install cargo-machete
       run: |
         cargo install cargo-machete --locked
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
deleted file mode 100644
index bbd74155ccf..00000000000
--- a/rust-toolchain.toml
+++ /dev/null
@@ -1,5 +0,0 @@
-[toolchain]
-channel = "1.73.0"
-components = [ "clippy", "rustfmt", "rust-src" ]
-targets = [ "wasm32-unknown-unknown" ]
-profile = "minimal"
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
new file mode 120000
index 00000000000..00f75390645
--- /dev/null
+++ b/rust-toolchain.toml
@@ -0,0 +1 @@
+toolchains/build/rust-toolchain.toml
\ No newline at end of file
diff --git a/toolchains/build/rust-toolchain.toml b/toolchains/build/rust-toolchain.toml
new file mode 100644
index 00000000000..bbd74155ccf
--- /dev/null
+++ b/toolchains/build/rust-toolchain.toml
@@ -0,0 +1,5 @@
+[toolchain]
+channel = "1.73.0"
+components = [ "clippy", "rustfmt", "rust-src" ]
+targets = [ "wasm32-unknown-unknown" ]
+profile = "minimal"
diff --git a/toolchains/lint/rust-toolchain.toml b/toolchains/lint/rust-toolchain.toml
new file mode 100644
index 00000000000..014ff528dcc
--- /dev/null
+++ b/toolchains/lint/rust-toolchain.toml
@@ -0,0 +1,4 @@
+[toolchain]
+channel = "nightly-2023-10-23"
+components = [ "clippy", "rustfmt" ]
+profile = "minimal"