Fix Mac CI (#3740)

Summary: Pull Request resolved: #3740

Reviewed By: huydhn

Differential Revision: D57797369

Pulled By: kirklandsign

fbshipit-source-id: e41201077368c518b8f63ef4b5f88d1c9fb7eb2a

Author: kirklandsign

.ci/scripts/setup-macos.sh

@@ -77,6 +77,13 @@ install_sccache() {
 
   export PATH="${SCCACHE_PATH}:${PATH}"
 
+  # Create temp directory for sccache shims if TMP_DIR doesn't exist
+  if [ -z "${TMP_DIR:-}" ]; then
+    TMP_DIR=$(mktemp -d)
+    trap 'rm -rfv ${TMP_DIR}' EXIT
+    export PATH="${TMP_DIR}:$PATH"
+  fi
+
   write_sccache_stub "${TMP_DIR}/c++"
   write_sccache_stub "${TMP_DIR}/cc"
   write_sccache_stub "${TMP_DIR}/clang++"