don't print warnings to CI

.github/scripts/unix.sh

@@ -58,8 +58,10 @@ function configure()
   fi
 
   # GTSAM_BUILD_WITH_MARCH_NATIVE=OFF: to avoid crashes in builder VMs
+  # CMAKE_CXX_FLAGS="-w": Suppress warnings to avoid IO latency in CI logs
   cmake $SOURCE_DIR \
       -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE:-Debug} \
+      -DCMAKE_CXX_FLAGS="-w" \
       -DGTSAM_BUILD_TESTS=${GTSAM_BUILD_TESTS:-OFF} \
       -DGTSAM_BUILD_UNSTABLE=${GTSAM_BUILD_UNSTABLE:-ON} \
       -DGTSAM_WITH_TBB=${GTSAM_WITH_TBB:-OFF} \