At least rust 1.51.0 is required

Ensure CI will catch if we start using features from newer versions.

Signed-off-by: Sean Young <[email protected]>

.github/workflows/release.yml

@@ -15,7 +15,7 @@ jobs:
       # checkout@v2 requires git 2.18 or higher, which is not in our image
       uses: actions/checkout@v1
     - name: Rust stable
-      run: rustup default stable
+      run: rustup default 1.51.0
     - name: Build
       run: cargo build --verbose --release
     - name: Run tests

.github/workflows/test.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Checkout sources
         uses: actions/checkout@v2
       - name: Rust stable
-        run: rustup default stable
+        run: rustup default 1.51.0
       - name: Run cargo fmt
         run: cargo fmt --all -- --check
       - name: Run cargo clippy
@@ -34,7 +34,7 @@ jobs:
       # checkout@v2 requires git 2.18 or higher, which is not in our image
       uses: actions/checkout@v1
     - name: Rust stable
-      run: rustup default stable
+      run: rustup default 1.51.0
     - name: Build
       run: cargo build --verbose
     - name: Run tests

docs/installing.rst

@@ -50,7 +50,7 @@ Then you can build the image using:
 Building Solang from source
 ---------------------------
 
-In order to build Solang from source, you will need rust 1.48.0 or higher,
+In order to build Solang from source, you will need rust 1.51.0 or higher,
 and a build of llvm based on the Solana llvm tree. There are a few patches which are not upstream yet.
 First, follow the steps below for installing llvm and then proceed from there.