Do not build project when only "monitor" target is passed

platformio/run/cli.py

@@ -104,6 +104,8 @@ def cli(
     is_test_running = CTX_META_TEST_IS_RUNNING in ctx.meta
 
     results = []
+    only_monitor = "monitor" in target and len(target) == 1
+    command_failed = False
     with fs.cd(project_dir):
         config = ProjectConfig.get_instance(project_conf)
         config.validate(environment)
@@ -111,65 +113,75 @@ def cli(
         if list_targets:
             return print_target_list(list(environment) or config.envs())
 
-        # clean obsolete build dir
-        if not disable_auto_clean:
-            build_dir = config.get("platformio", "build_dir")
-            try:
-                clean_build_dir(build_dir, config)
-            except ProjectError as exc:
-                raise exc
-            except:  # pylint: disable=bare-except
-                click.secho(
-                    "Can not remove temporary directory `%s`. Please remove "
-                    "it manually to avoid build issues" % build_dir,
-                    fg="yellow",
+        if not only_monitor:
+            # clean obsolete build dir
+            if not disable_auto_clean:
+                build_dir = config.get("platformio", "build_dir")
+                try:
+                    clean_build_dir(build_dir, config)
+                except ProjectError as exc:
+                    raise exc
+                except:  # pylint: disable=bare-except
+                    click.secho(
+                        "Can not remove temporary directory `%s`. Please remove "
+                        "it manually to avoid build issues" % build_dir,
+                        fg="yellow",
+                    )
+
+            handle_legacy_libdeps(project_dir, config)
+
+            default_envs = config.default_envs()
+            for env in config.envs():
+                skipenv = any(
+                    [
+                        environment and env not in environment,
+                        not environment and default_envs and env not in default_envs,
+                    ]
+                )
+                if skipenv:
+                    results.append({"env": env})
+                    continue
+
+                # print empty line between multi environment project
+                if not silent and any(r.get("succeeded") is not None for r in results):
+                    click.echo()
+
+                results.append(
+                    process_env(
+                        ctx,
+                        env,
+                        config,
+                        target,
+                        upload_port,
+                        jobs,
+                        program_args,
+                        is_test_running,
+                        silent,
+                        verbose,
+                    )
                 )
 
-        handle_legacy_libdeps(project_dir, config)
-
-        default_envs = config.default_envs()
-        for env in config.envs():
-            skipenv = any(
-                [
-                    environment and env not in environment,
-                    not environment and default_envs and env not in default_envs,
-                ]
-            )
-            if skipenv:
-                results.append({"env": env})
-                continue
-
-            # print empty line between multi environment project
-            if not silent and any(r.get("succeeded") is not None for r in results):
-                click.echo()
-
-            results.append(
-                process_env(
-                    ctx,
-                    env,
-                    config,
-                    environment,
-                    target,
-                    upload_port,
-                    monitor_port,
-                    jobs,
-                    program_args,
-                    is_test_running,
-                    silent,
-                    verbose,
-                )
-            )
-
-    command_failed = any(r.get("succeeded") is False for r in results)
-
-    if not is_test_running and (command_failed or not silent) and len(results) > 1:
-        print_processing_summary(results, verbose)
+            command_failed = any(r.get("succeeded") is False for r in results)
+            if (
+                not is_test_running
+                and (command_failed or not silent)
+                and len(results) > 1
+            ):
+                print_processing_summary(results, verbose)
 
     # Reset custom project config
     app.set_session_var("custom_project_conf", None)
 
     if command_failed:
         raise exception.ReturnErrorCode(1)
+
+    if "monitor" in target and "nobuild" not in target:
+        ctx.invoke(
+            device_monitor_cmd,
+            port=monitor_port,
+            environment=environment[0] if environment else None,
+        )
+
     return True
 
 
@@ -177,10 +189,8 @@ def process_env(
     ctx,
     name,
     config,
-    environments,
     targets,
     upload_port,
-    monitor_port,
     jobs,
     program_args,
     is_test_running,
@@ -208,17 +218,6 @@ def process_env(
     if not is_test_running and (not silent or not result["succeeded"]):
         print_processing_footer(result)
 
-    if (
-        result["succeeded"]
-        and "monitor" in ep.get_build_targets()
-        and "nobuild" not in ep.get_build_targets()
-    ):
-        ctx.invoke(
-            device_monitor_cmd,
-            port=monitor_port,
-            environment=environments[0] if environments else None,
-        )
-
     return result