Re: [RFC PATCH 0/9] tests: run python tests under the build/tests/venv environment

[Paolo Bonzini]

On 5/13/22 02:06, John Snow wrote:
> The only downside I am really frowning at is that I will have to
> replicate some "update the venv if it's outdated" logic that is usually
> handled by the Make system in the venv bootstrapper. Still, I think it's
> probably the only way to hit all of the requirements here without trying
> to concoct a fairly complex Makefile.
>
> any thoughts? If not, I'll just move on to trying to hack up that
> version next instead.

I would not even bother with keeping the venv up to date.  Just initialize
it in configure, this is exactly what configure remains useful for in the
Meson-based world:

- add configure options --enable-python-qemu={enabled,system,internal,pip,
auto}/--disable-python-qemu (auto means system>internal>pip>disabled; enabled 
means
system>internal>pip>error) and matching CONFIG_PYTHON_QEMU=y to
config-host.mak

- use CONFIG_PYTHON_QEMU to enable/disable iotests in 
tests/qemu-iotests/meson.build

- add a configure option --enable-avocado=
{system,pip,auto,enabled}/--disable-avocado and matching
CONFIG_AVOCADO=y to config-host.mak

- use it to enable/disable acceptance tests in tests/Makefile.include

- build the venv in configure and use the options to pick the right pip install
commands, like

has_python_module() {
  $python -c "import $1" > /dev/null 2>&1
}

# do_pip VENV-PATH VAR PACKAGE [PATH] -- PIP-OPTIONS
do_pip() {
    local num_args source
    num_args=5
    test $4 = '--' && num_args=4
    eval source=\$$2
    # Try to resolve the package using a system install
    case $source in
      enabled|auto|system)
        if has_python_module $3; then
          source=system
        elif test $source = system; then
          error_exit "Python package $3 not installed"
        fi
    esac
    # See if a bundled copy is present
    case $source in
      enabled|auto|internal)
        if test $num_args = 5 && test -f $4/setup.cfg; then
          source=internal
        elif test $source = internal; then
          error_exit "Sources for Python package $3 not found in the QEMU source 
tree"
        fi
    esac
    # Install the bundled copy or let pip download the package
    case $source in
      internal)
        # The Pip error message should be clear enough
        (cd $1 && . bin/activate && pip install "$@") || exit 1
      ;;
      enabled|auto|pip)
        shift $num_args
        if (cd $1 && . bin/activate && pip install "$@"); then
          source=pip
        elif test $source = auto; then
          source=disabled
        else
          # The Pip error message should be clear enough
          exit 1
        fi
      ;;
    esac
    eval $2=\$source
}

rm -rf venv/
$python -m venv venv/
do_pip venv/ enable_python_qemu qemu.qmp python/qemu -- qemu.qmp
do_pip venv/ enable_avocado avocado -- -r tests/requirements.txt