maybe fix

Author: rickeylev

python/private/stage1_bootstrap_template.sh

@@ -61,14 +61,17 @@ if [[ "$IS_ZIPFILE" == "1" ]]; then
 
 else
   function find_runfiles_root() {
+    local maybe_root=""
     if [[ -n "${RUNFILES_DIR:-}" ]]; then
-      echo "$RUNFILES_DIR"
-      return 0
+      maybe_root="$RUNFILES_DIR"
     elif [[ "${RUNFILES_MANIFEST_FILE:-}" = *".runfiles_manifest" ]]; then
-      echo "${RUNFILES_MANIFEST_FILE%%.runfiles_manifest}.runfiles"
-      return 0
+      maybe_root="${RUNFILES_MANIFEST_FILE%%.runfiles_manifest}.runfiles"
     elif [[ "${RUNFILES_MANIFEST_FILE:-}" = *".runfiles/MANIFEST" ]]; then
-      echo "${RUNFILES_MANIFEST_FILE%%.runfiles/MANIFEST}.runfiles"
+      maybe_root="${RUNFILES_MANIFEST_FILE%%.runfiles/MANIFEST}.runfiles"
+    fi
+
+    if [[ -n "$maybe_root" && -e "$maybe_root/$STAGE2_BOOTSTRAP" ]]; then
+      echo "$maybe_root"
       return 0
     fi