Fix

lib/installer.js

@@ -171,6 +171,9 @@ function downloadJava(version) {
         }
         const fileName = refs[0].slice('<a href="'.length, refs[0].length - '">'.length);
         const dest = yield tc.downloadTool(`https://static.azul.com/zulu/bin/${fileName}`);
+        if (dest) {
+            throw new Error(fs.readdirSync(dest).toString());
+        }
         return path.join(dest, fileName);
     });
 }

src/installer.ts

@@ -178,5 +178,8 @@ async function downloadJava(version: string): Promise<string> {
   const dest = await tc.downloadTool(
     `https://static.azul.com/zulu/bin/${fileName}`
   );
+  if (dest) {
+    throw new Error(fs.readdirSync(dest).toString());
+  }
   return path.join(dest, fileName);
 }