Re: [PATCH] tests/functional: add --debug CLI arg

[Thomas Huth <thuth@redhat.com>]

On 21/07/2025 22.38, John Snow wrote:
> On Thu, Jul 17, 2025 at 4:44 AM Alex Bennée <alex.bennee@linaro.org> wrote:
...
>> Am I holding it wrong?
>>
>>    ➜  ./pyvenv/bin/python ../../tests/functional/test_aarch64_virt.py --help
>>    Traceback (most recent call last):
>>      File "/home/alex/lsrc/qemu.git/builds/all/../../tests/functional/test_aarch64_virt.py", line 16, in <module>
>>        from qemu_test import QemuSystemTest, Asset, exec_command_and_wait_for_pattern
>>      File "/home/alex/lsrc/qemu.git/tests/functional/qemu_test/__init__.py", line 14, in <module>
>>        from .testcase import QemuBaseTest, QemuUserTest, QemuSystemTest
>>      File "/home/alex/lsrc/qemu.git/tests/functional/qemu_test/testcase.py", line 26, in <module>
>>        from qemu.machine import QEMUMachine
>>    ModuleNotFoundError: No module named 'qemu'
>>
>> I thought the point of the venv is we had all the modules we need
>> automatically available to the PYTHONPATH?
> 
> As Thomas points out, "qemu" is special since it's already in the
> tree. There has been some dragging-of-feet by yours-truly because
> installing the "qemu" module by default when running configure
> introduces a considerable startup lag time, and the module is not
> actually needed for the simple configuration and building of QEMU -
> only testing.
> 
> It's something I want to fix, but must admit to being a bit stumped as
> to how I will bridge that gap long term. Currently, all of the modules
> we need are in the tree with no dependencies, so it can be fixed with
> a simple PYTHONPATH hack. However, if I actually remove the QMP
> library from the tree like I have wanted to, then we need pip to do a
> real install and process dependencies, and this creates some
> complications and extra startup lag.

Wouldn't it be possible to add the module as a wheel in python/wheels/ ? 
That's maybe the easiest solution, isn't it?

> Naively, I think adding a "just in time installation of testing
> dependencies" when you go to run a testing command from "make XXXX"
> might be sufficient for us, possibly in conjunction with a configure
> flag that lets you pre-load testing dependencies.

We could likely re-use "make check-venv" for the functional tests ... it's 
already installed in that case. However, you then still have to remember to 
call it first before you can run a test directly, without the Makefile wrappers.

  Thomas