fix(cli): exit non-zero when --auto-build fails

concore_cli/commands/build.py

@@ -318,9 +318,12 @@ def build_workflow(
                     console.print("[green]✓[/green] Build completed")
                 except subprocess.CalledProcessError as e:
                     progress.stop()
-                    console.print("[yellow]Build failed[/yellow]")
+                    console.print("[red]Build failed:[/red]")
+                    if e.stdout:
+                        console.print(e.stdout)
                     if e.stderr:
                         console.print(e.stderr)
+                    raise
 
     run_command = "docker compose up" if compose else "./run"
     if exec_type == "windows":

tests/test_cli.py

@@ -882,6 +882,39 @@ def test_build_command_shared_source_specialization_merges_edge_params(self):
             self.assertIn("PORT_NAME_B_C", content)
             self.assertIn("PORT_B_C", content)
 
+    def test_build_command_auto_build_failure_exits_nonzero(self):
+        real_run = subprocess.run
+
+        def fake_run(cmd, *args, **kwargs):
+            if Path(str(cmd[0])).name in ("build", "build.bat"):
+                raise subprocess.CalledProcessError(1, cmd, output="", stderr="boom")
+            return real_run(cmd, *args, **kwargs)
+
+        with self.runner.isolated_filesystem(temp_dir=self.temp_dir):
+            result = self.runner.invoke(cli, ["init", "test-project"])
+            self.assertEqual(result.exit_code, 0)
+
+            with patch.object(subprocess, "run", side_effect=fake_run):
+                result = self.runner.invoke(
+                    cli,
+                    [
+                        "build",
+                        "test-project/workflow.graphml",
+                        "--source",
+                        "test-project/src",
+                        "--output",
+                        "out",
+                        "--type",
+                        "posix",
+                        "--auto-build",
+                    ],
+                )
+
+            self.assertNotEqual(result.exit_code, 0)
+            self.assertIn("boom", result.output)
+            self.assertIn("Build failed", result.output)
+            self.assertNotIn("Workflow ready", result.output)
+
     def test_build_command_existing_output(self):
         with self.runner.isolated_filesystem(temp_dir=self.temp_dir):
             result = self.runner.invoke(cli, ["init", "test-project"])