codex/patches/aws-lc-sys_windows_msvc_memcmp_probe.patch

diff --git a/builder/cc_builder.rs b/builder/cc_builder.rs
--- a/builder/cc_builder.rs
+++ b/builder/cc_builder.rs
@@ -667,12 +667,24 @@
         if cargo_env("HOST") != target() {
             return;
         }
+
+        let bazel_execroot = Self::bazel_execroot(self.manifest_dir.as_path());
+        if bazel_execroot.is_some() && target().ends_with("windows-msvc") {
+            // This probe guards a GCC memcmp miscompile. Under Bazel's
+            // hermetic Windows/MSVC build-script toolchain we drive clang with
+            // MinGW-flavored CFLAGS, which is good enough for compiling
+            // aws-lc but not for linking and executing this standalone test
+            // binary. Skip the probe in that configuration instead of failing
+            // the whole build script.
+            emit_warning("Skipping memcmp probe for Bazel windows-msvc build scripts.");
+            return;
+        }

         let basename = "memcmp_invalid_stripped_check";
         let exec_path = out_dir().join(basename);
         let memcmp_build = cc::Build::default();
         let memcmp_compiler = memcmp_build.get_compiler();
         if !memcmp_compiler.is_like_clang() && !memcmp_compiler.is_like_gnu() {
             // The logic below assumes a Clang or GCC compiler is in use
             return;
         }
@@ -701,7 +713,7 @@
                 memcmp_compile_args.push(flag.into());
             }
         }

-        if let Some(execroot) = Self::bazel_execroot(self.manifest_dir.as_path()) {
+        if let Some(execroot) = bazel_execroot {
             // In Bazel build-script sandboxes, `cc` can pass `bazel-out/...` args
             // relative to the execroot while the process runs from elsewhere.
             // Normalize those args to absolute paths so this check can still link.