Windows treat link warnings as error

.github/workflows/cross.yml

@@ -116,6 +116,8 @@ jobs:
   cargo-xwin:
     if: github.repository_owner == 'aws'
     runs-on: ubuntu-latest
+    env:
+      RUSTFLAGS: '-Clink-arg=/WX'
     steps:
       - name: Install build dependencies
         run: |
@@ -142,6 +144,8 @@ jobs:
     if: github.repository_owner == 'aws'
     name: ${{ matrix.target }}
     runs-on: windows-latest
+    env:
+      RUSTFLAGS: '-Clink-arg=/WX'
     strategy:
       fail-fast: false
       matrix:
@@ -180,6 +184,8 @@ jobs:
     if: github.repository_owner == 'aws'
     name: aarch64-pc-windows-msvc
     runs-on: windows-latest
+    env:
+      RUSTFLAGS: '-Clink-arg=/WX'
     steps:
       - uses: actions/checkout@v3
         with:

aws-lc-sys/builder/cmake_builder.rs

@@ -68,15 +68,16 @@ impl CmakeBuilder {
 
     fn get_cmake_config(&self) -> cmake::Config {
         let mut cmake_cfg = cmake::Config::new(&self.manifest_dir);
-        // See issue: https://github.com/aws/aws-lc-rs/issues/453
-        cmake_cfg.static_crt(true);
+        if cargo_env("CARGO_ENCODED_RUSTFLAGS").contains("-Ctarget-feature=+crt-static") {
+            // See issue: https://github.com/aws/aws-lc-rs/issues/453
+            cmake_cfg.static_crt(true);
+        }
         cmake_cfg
     }
 
     #[allow(clippy::too_many_lines)]
     fn prepare_cmake_build(&self) -> cmake::Config {
         let mut cmake_cfg = self.get_cmake_config();
-
         if OutputLibType::default() == OutputLibType::Dynamic {
             cmake_cfg.define("BUILD_SHARED_LIBS", "1");
         } else {
@@ -91,6 +92,7 @@ impl CmakeBuilder {
                 cmake_cfg.define("CMAKE_BUILD_TYPE", "release");
             }
         } else if target_os() == "windows" {
+            // See issue: https://github.com/aws/aws-lc-rs/issues/453
             cmake_cfg.define("CMAKE_BUILD_TYPE", "relwithdebinfo");
         } else {
             cmake_cfg.define("CMAKE_BUILD_TYPE", "debug");