force use of homebrew clang (like upstream)

Author: mattip

.github/workflows/posix.yml

@@ -93,12 +93,13 @@ jobs:
       run: |
         echo "DOCKER_TEST_IMAGE=$(echo multibuild/xenial_${{ matrix.PLAT}})" >> $GITHUB_ENV;
 
-    - name: Setup gcc from homebrew
+    - name: Setup clang from homebrew
       if: ${{ matrix.os == 'macos-13' }}
       run: |
         brew reinstall gcc
         brew install coreutils
         brew install llvm
+        echo "CC=/opt/homebrew/opt/llvm/bin/clang" >> $GITHUB_ENV;
 
     - name: Print some Environment variable
       run: |

tools/build_steps.sh

@@ -206,6 +206,12 @@ function do_build_lib {
         echo "Due to the qemu versions 7.2 causing utest cases to fail,"
         echo "the utest dsdot:dsdot_n_1 have been temporarily disabled."
     fi
+    echo start building
+    echo "========== gcc ============="
+    echo path $PATH
+    echo gcc path $(which gcc)
+    echo gcc version $(gcc --version)
+    echo "========== gcc ============="
     if [ "$dynamic_list" != "" ]; then
         CFLAGS="$CFLAGS -fvisibility=protected -Wno-uninitialized" \
         make BUFFERSIZE=20 DYNAMIC_ARCH=1 QUIET_MAKE=1 \
@@ -220,11 +226,6 @@ function do_build_lib {
             BINARY="$bitness" $interface_flags \
             TARGET="$target"
     fi
-    echo start building
-    echo "========== gcc ============="
-    echo gcc path $(which gcc)
-    echo gcc version $(gcc --version)
-    echo "========== gcc ============="
     make PREFIX=$BUILD_PREFIX $interface_flags install
     popd
     if [ "$nightly" = "1" ]; then