rust-toolchain: Migrate to TOML version of rust-toolchain

.changelog/4727.internal.md

@@ -0,0 +1 @@
+rust-toolchain: Migrate to TOML version of rust-toolchain

.github/workflows/ci-lint.yml

@@ -48,9 +48,7 @@ jobs:
         with:
           go-version: "1.17.x"
       - name: Set up Rust
-        uses: actions-rs/toolchain@v1
-        with:
-          components: clippy
+        run: rustup show
       - name: Install dependencies
         run: |
           sudo apt-get update

.github/workflows/ci-reproducibility.yml

@@ -37,17 +37,13 @@ jobs:
           # NOTE: We make a git checkout to a unique directory for each build to
           # catch reproducibility issues with code in different local paths.
           path: build${{ matrix.build_number }}
-      - name: Copy rust-toolchain file
-        run: |
-          # Copy rust-toolchain file as it gets checked out into a subdir which is not
-          # supported by actions-rs/toolchain.
-          cp build${{ matrix.build_number }}/rust-toolchain .
       - name: Set up Go 1.17
         uses: actions/setup-go@v3
         with:
           go-version: "1.17.x"
       - name: Set up Rust
-        uses: actions-rs/toolchain@v1
+        working-directory: build${{ matrix.build_number }}
+        run: rustup show
       - name: Install Oasis Node prerequisites
         run: |
           sudo apt-get update

.github/workflows/release-dev.yml

@@ -38,7 +38,7 @@ jobs:
         with:
           go-version: "1.17.x"
       - name: Set up Rust
-        uses: actions-rs/toolchain@v1
+        run: rustup show
       - name: Install Oasis Node prerequisites
         run: |
           sudo apt-get update

.github/workflows/release.yml

@@ -42,7 +42,7 @@ jobs:
           go-version: "1.17.x"
 
       - name: Set up Rust
-        uses: actions-rs/toolchain@v1
+        run: rustup show
 
       - name: Install Oasis Node prerequisites
         run: |

docs/development-setup/prerequisites.md

@@ -103,7 +103,7 @@ Core:
 * Oasis Core's Rust toolchain version with Fortanix SGX target.
 
   The version of the Rust toolchain we use in Oasis Core is specified in the
-  [rust-toolchain] file.
+  [`rust-toolchain.toml`] file.
 
   The rustup-installed versions of `cargo`, `rustc` and other tools will
   [automatically detect this file and use the appropriate version of the Rust
@@ -126,17 +126,10 @@ Core:
   active toolchain
   ----------------
 
-  nightly-2022-04-13-x86_64-unknown-linux-gnu (overridden by '/code/rust-toolchain')
+  nightly-2022-04-13-x86_64-unknown-linux-gnu (overridden by '/code/rust-toolchain.toml')
   rustc 1.62.0-nightly (52ca603da 2022-04-12)
   ```
 
-  Then add the Fortanix SGX Rust target to this version of the Rust toolchain by
-  running:
-
-  ```
-  rustup target add x86_64-fortanix-unknown-sgx
-  ```
-
 * (**OPTIONAL**) [gofumpt] and [goimports].
 
   Required if you plan to change any of the Go code in order for automated code
@@ -236,8 +229,8 @@ where the code has been checked out.
 [download `rustup-init` executable for your platform]:
   https://github.com/rust-lang/rustup#other-installation-methods
 [Rust]: https://www.rust-lang.org/
-[rust-toolchain]:
-  https://github.com/oasisprotocol/oasis-core/tree/master/rust-toolchain
+[`rust-toolchain.toml`]:
+  https://github.com/oasisprotocol/oasis-core/tree/master/rust-toolchain.toml
 [rust-toolchain-precedence]:
   https://github.com/rust-lang/rustup/blob/master/README.md#override-precedence
 [Fortanix Rust EDP]: https://edp.fortanix.com

rust-toolchain.toml

@@ -0,0 +1,4 @@
+[toolchain]
+channel = "nightly-2022-04-13"
+targets = ["x86_64-fortanix-unknown-sgx"]
+components = ["clippy", "rustfmt"]