Method BeginVirtualEnvPhase

Modules/PythonInstaller/src/QmitkPipInstaller.cpp:401–439

Either kicks off a `python -m venv ` subprocess (asynchronous) or, if the venv is unnecessary or already exists, activates it and dispatches synchronously to the next phase.

// the venv is unnecessary or already exists, activates it and dispatches
// synchronously to the next phase.
void QmitkPipInstaller::BeginVirtualEnvPhase()
{
  if (m_Spec.venvName.empty() || mitk::PythonHelper::VirtualEnvExists(m_Spec.venvName))
  {
    // No venv needed or already exists - just activate and move on.
    if (!m_Spec.venvName.empty() && !mitk::PythonHelper::ActivateVirtualEnv(m_Spec.venvName))
    {
      m_State = State::Failed;
      emit ErrorOccurred("Failed to activate virtual environment.");
      emit InstallFinished(false);
      return;
    }

    if (m_Spec.upgradePipFirst)
    {
      this->StartPipUpgrade();
    }
    else
    {
      emit ResolveStarted();
      this->StartResolveGroup();
    }
    return;
  }

  const auto python = this->RequirePythonExecutable();

  if (python.isEmpty())
    return;

  m_State = State::CreatingVirtualEnv;
  m_CreatedVirtualEnv = true;
  emit VirtualEnvCreationStarted();

  const auto venvPath = mitk::PythonHelper::GetVirtualEnvPath(m_Spec.venvName);
  QStringList args = { "-m", "venv", QString::fromStdString(venvPath.string()) };
  MITK_INFO << FormatCommand(python, args).toStdString();
  m_Process->start(python, args);
}

void QmitkPipInstaller::StartPipUpgrade()
{