Pin Rust 1.93.0 for polkadot-sdk builds

Author: rockbmb

.github/workflows/build-release-binaries.yaml

@@ -1,5 +1,8 @@
 name: Build and Attach Binaries to Release
 
+env:
+  TOOLCHAIN_STABLE: "1.93.0"
+
 on:
   release:
     types:
@@ -35,7 +38,7 @@ jobs:
         uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: stable
+          toolchain: ${{ env.TOOLCHAIN_STABLE }}
           override: true
 
       - name: Add apple target

.github/workflows/rust-checks.yaml

@@ -14,15 +14,18 @@ env:
   RUST_BACKTRACE: 1
   # pin nightly to avoid constantly throwing out cache
   TOOLCHAIN_FMT: nightly-2026-01-01
+  # must match polkadot-sdk's CI toolchain (see .github/env in polkadot-sdk)
+  TOOLCHAIN_STABLE: "1.93.0"
 
 jobs:
   doc:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - name: Install Rust stable
+      - name: Install Rust ${{ env.TOOLCHAIN_STABLE }}
         uses: dtolnay/rust-toolchain@stable
         with:
+          toolchain: ${{ env.TOOLCHAIN_STABLE }}
           targets: wasm32-unknown-unknown
       - uses: Swatinem/rust-cache@v2
         with:
@@ -58,10 +61,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - name: Install Rust stable
+      - name: Install Rust ${{ env.TOOLCHAIN_STABLE }}
         uses: dtolnay/rust-toolchain@stable
         with:
-          toolchain: stable
+          toolchain: ${{ env.TOOLCHAIN_STABLE }}
           targets: wasm32-unknown-unknown
           components: rustfmt, clippy, rust-src
       - uses: Swatinem/rust-cache@v2
@@ -75,23 +78,22 @@ jobs:
       - name: cargo clippy
         uses: actions-rs-plus/clippy-check@v2
         with:
-          toolchain: stable
+          toolchain: ${{ env.TOOLCHAIN_STABLE }}
           args: --all-targets --all-features --locked --no-deps -- --deny warnings
 
   test:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        toolchain: [stable]
     runs-on: ${{ matrix.os }}
     env:
       RUSTFLAGS: "-Cdebug-assertions=y"
     steps:
       - uses: actions/checkout@v4
-      - name: Install Rust ${{ matrix.toolchain }}
+      - name: Install Rust ${{ env.TOOLCHAIN_STABLE }}
         uses: dtolnay/rust-toolchain@stable
         with:
-          toolchain: ${{ matrix.toolchain }}
+          toolchain: ${{ env.TOOLCHAIN_STABLE }}
           targets: wasm32-unknown-unknown
       - uses: Swatinem/rust-cache@v2
       - name: Install Protoc

.github/workflows/rust-docs.yaml

@@ -1,5 +1,8 @@
 name: Update rust docs
 
+env:
+  TOOLCHAIN_STABLE: "1.93.0"
+
 on:
   push:
     branches:
@@ -27,10 +30,10 @@ jobs:
       - name: Install Rust Stable
         uses: dtolnay/rust-toolchain@stable
         with:
-          toolchain: stable
+          toolchain: ${{ env.TOOLCHAIN_STABLE }}
           targets: wasm32-unknown-unknown
           components: rust-src
-        
+
       - name: Check if the README is up to date.
         run: |
           cargo install cargo-rdme --locked -q

rust-toolchain.toml

@@ -1,5 +1,5 @@
 [toolchain]
-channel = "stable"
+channel = "1.93.0"
 components = [
 	"rust-src",
 	"rustc-dev",