Hotfix unbound $PY variable breaking cargo script (#11209)

If `set -u` is configured, then it errors that `$PY` is not set. [ci skip-rust] [ci skip-build-wheels]
pantsbuild · Nov 19, 2020 · 9b3b481 · 9b3b481
1 parent 0066bdc
commit 9b3b481
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/build-support/common.sh b/build-support/common.sh
@@ -70,7 +70,7 @@ function git_merge_base() {
 }
 
 function determine_python() {
-  if [[ -n "${PY}" ]]; then
+  if [[ -n "${PY:-}" ]]; then
     echo "${PY}"
     return 0
   fi