ProcessBuilder crash if task has no output

[zedaav]

Example task:

tasks:
  build_compiled_resources:
    description: Build the compiled Qt resources files
    emoji: ":snake:.:hammer: "
    appendToDeps: build
    params:
      cmd:
        [
          "pyside6-rcc",
          "-o",
          "${PROJECTDIR}\\src\\main_qrc.py",
          "${PROJECTDIR}\\res\\main.qrc",
        ]
    builder: nmk_base.common.ProcessBuilder

Logs:

2024-06-03 15:28:26.987 (D) nmk 🐛 - New task build_executable - model.py:add_task:115
2024-06-03 15:28:26.988 (D) nmk 🐛 - Updating PROJECTFILES now that all files are loaded - loader.py:load_model_from_files:72
2024-06-03 15:28:26.989 (D) nmk 🐛 - Starting the build! - build.py:build:85
2024-06-03 15:28:26.989 (D) [build_compiled_resources] 🐛 - Task misses either inputs or outputs - build.py:needs_build:140
2024-06-03 15:28:26.990 (I) [build_compiled_resources] 🐍.🔨  - Build the compiled Qt resources files - build.py:task_prolog:105
2024-06-03 15:28:26.991 (D) nmk 🐛 - Running command: ['pyside6-rcc', '-o', 'C:\\Users\\xxx\\src\\main_qrc.py', 'C:\\Users\\xxx\\res\\main.qrc'] - utils.py:run_with_logs:14
2024-06-03 15:28:27.422 (D) nmk 🐛 - >> rc: 0 - utils.py:run_with_logs:16
2024-06-03 15:28:27.423 (D) nmk 🐛 - >> stderr: - utils.py:run_with_logs:17
2024-06-03 15:28:27.424 (D) nmk 🐛 - >> stdout: - utils.py:run_with_logs:19
2024-06-03 15:28:27.425 (E) nmk 💀 - An error occurred during task build_compiled_resources build: list index out of range - __main__.py:nmk:29
2024-06-03 15:28:27.428 (D) nmk 🐛 -   File "C:\Users\xxx\venv\Lib\site-packages\nmk\__main__.py", line 23, in nmk - __main__.py:nmk:30
2024-06-03 15:28:27.429 (D) nmk 🐛 -     if NmkBuild(model).build(): - __main__.py:nmk:30
2024-06-03 15:28:27.430 (D) nmk 🐛 -        ^^^^^^^^^^^^^^^^^^^^^^^ - __main__.py:nmk:30
2024-06-03 15:28:27.430 (D) nmk 🐛 -   File "C:\Users\xxx\venv\Lib\site-packages\nmk\build.py", line 94, in build - __main__.py:nmk:30
2024-06-03 15:28:27.431 (D) nmk 🐛 -     self.task_build(task, build_logger) - __main__.py:nmk:30
2024-06-03 15:28:27.432 (D) nmk 🐛 -   File "C:\Users\xxx\venv\Lib\site-packages\nmk\build.py", line 120, in task_build - __main__.py:nmk:30
2024-06-03 15:28:27.433 (D) nmk 🐛 -     raise e if isinstance(e, NmkStopHereError) else Exception(f"An error occurred during task {task.name} build: {e}").with_traceback(e.__traceback__) - __main__.py:nmk:30
2024-06-03 15:28:27.434 (D) nmk 🐛 -   File "C:\Users\xxx\venv\Lib\site-packages\nmk\build.py", line 118, in task_build - __main__.py:nmk:30
2024-06-03 15:28:27.434 (D) nmk 🐛 -     task.builder.build(**params) - __main__.py:nmk:30
2024-06-03 15:28:27.435 (D) nmk 🐛 -   File "C:\Users\xxx\venv\Lib\site-packages\nmk_base\common.py", line 169, in build - __main__.py:nmk:30
2024-06-03 15:28:27.436 (D) nmk 🐛 -     self.main_output.touch() - __main__.py:nmk:30
2024-06-03 15:28:27.437 (D) nmk 🐛 -     ^^^^^^^^^^^^^^^^ - __main__.py:nmk:30
2024-06-03 15:28:27.438 (D) nmk 🐛 -   File "C:\Users\xxx\venv\Lib\site-packages\nmk\model\builder.py", line 40, in main_output - __main__.py:nmk:30
2024-06-03 15:28:27.439 (D) nmk 🐛 -     return self.outputs[0] - __main__.py:nmk:30
2024-06-03 15:28:27.440 (D) nmk 🐛 -            ~~~~~~~~~~~~^^^ - __main__.py:nmk:30
2024-06-03 15:28:27.441 (D) nmk 🐛 -  - __main__.py:nmk:30