add comment
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index c55d6bb..5f04992 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -23,6 +23,7 @@
             _ver="['3.8', '3.9', '3.10']"
             _cache="1"
           else 
+            # 3.8 instead of '3.8' to make github act work.
             _ver="[3.8]"
             _cache="0"
           fi