Having an issue with pulumi_docker and environment variables. This works fine:

mock_image = docker.Image('mock-server-image',
                          build=docker.DockerBuild(context='../',
                                                   dockerfile=f'../Dockerfile'),
                          image_name=f'{repo.repository_url}',
                          registry=registry)

But as soon as I add an environment variable …

mock_image = docker.Image('mock-server-image',
                          build=docker.DockerBuild(context='../',
                                                   dockerfile=f'../Dockerfile',
                                                   env={'MOCK_PORT': '80'}),
                          image_name=f'{repo.repository_url}',
                          registry=registry)

I get an error:

FileNotFoundError: [Errno 2] No such file or directory: 'docker': 'docker'