chore(cli): improve error message when bootstrap can't find stacks (#…

…15538)

The current error message is kind of confusing.


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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/aws-cdk/lib/cdk-toolkit.ts

@@ -338,17 +338,23 @@ export class CdkToolkit {
    *             all stacks are implicitly selected.
    * @param toolkitStackName the name to be used for the CDK Toolkit stack.
    */
-  public async bootstrap(environmentSpecs: string[], bootstrapper: Bootstrapper, options: BootstrapEnvironmentOptions): Promise<void> {
+  public async bootstrap(userEnvironmentSpecs: string[], bootstrapper: Bootstrapper, options: BootstrapEnvironmentOptions): Promise<void> {
     // If there is an '--app' argument and an environment looks like a glob, we
     // select the environments from the app. Otherwise use what the user said.
 
     // By default glob for everything
-    environmentSpecs = environmentSpecs.length > 0 ? environmentSpecs : ['**'];
+    const environmentSpecs = userEnvironmentSpecs.length > 0 ? [...userEnvironmentSpecs] : ['**'];
 
     // Partition into globs and non-globs (this will mutate environmentSpecs).
     const globSpecs = partition(environmentSpecs, looksLikeGlob);
     if (globSpecs.length > 0 && !this.props.cloudExecutable.hasApp) {
-      throw new Error(`'${globSpecs}' is not an environment name. Run in app directory to glob or specify an environment name like \'aws://123456789012/us-east-1\'.`);
+      if (userEnvironmentSpecs.length > 0) {
+        // User did request this glob
+        throw new Error(`'${globSpecs}' is not an environment name. Specify an environment name like 'aws://123456789012/us-east-1', or run in a directory with 'cdk.json' to use wildcards.`);
+      } else {
+        // User did not request anything
+        throw new Error('Specify an environment name like \'aws://123456789012/us-east-1\', or run in a directory with \'cdk.json\'.');
+      }
     }
 
     const environments: cxapi.Environment[] = [