diff --git a/src/build.js b/src/build.js
index 0232c9f..1bd0e0d 100644
--- a/src/build.js
+++ b/src/build.js
@@ -1,5 +1,12 @@
 'use strict'
 
+// Attempt to download GitLab job artifact and failover to GitHub if unsuccessful.
+// In GitLab Pages, the latest job status will be marked as unknown/failed if the repo has newer commit.
+// The link to download the latest job artifact will also be unavailable when that happens,
+// unless manually queried through API.
+// Instead of using the API, I find it easier to failover to GitHub.
+// ref: https://gitlab.com/gitlab-org/gitlab/-/issues/29257
+
 const { stream: gotStream } = require('got')
 const got = require('got')
 const unzip = require('extract-zip')