Warn if the action ends up not installing any .NET version.

dist/index.js

@@ -526,6 +526,9 @@ function run() {
                 if (fs.existsSync(globalJsonPath)) {
                     versions.push(getVersionFromGlobalJson(globalJsonPath));
                 }
+                else {
+                    core.info(`global.json wasn't found in the root directory. No .NET version will be installed.`);
+                }
             }
             if (versions.length) {
                 const quality = core.getInput('dotnet-quality');

src/setup-dotnet.ts

@@ -46,6 +46,10 @@ export async function run() {
       const globalJsonPath = path.join(process.cwd(), 'global.json');
       if (fs.existsSync(globalJsonPath)) {
         versions.push(getVersionFromGlobalJson(globalJsonPath));
+      } else {
+        core.info(
+          `global.json wasn't found in the root directory. No .NET version will be installed.`
+        );
       }
     }