diff --git a/index.js b/index.js
index bc089a6a3..a2dce5492 100644
--- a/index.js
+++ b/index.js
@@ -288,6 +288,8 @@ function logError(error) {
 
 function parseNpmVersionOutput(output) {
   const npmVersionStr = output.trim().split(EOL).pop();
+  console.log('[parseNpmVersionOutput] output:', output);
+  console.log('[parseNpmVersionOutput] npmVersionStr:', npmVersionStr);
   const version = npmVersionStr.replace(/^v/, '');
   return version;
 }