Following up here from the thread above. After a lot of painful experimentation I settled on this work around - bottom line

pulumi/actions@v3

and

poetry

don't play nice together in a github workflow environment. So instead of simply being able to do

# ----------------------------------------------
            #          install & configure poetry
            # ----------------------------------------------
            - name: Install Poetry
              uses: snok/install-poetry@v1.1.6
              with:
                  virtualenvs-create: true

            - name: Install dependencies
              run: |
                  poetry install --no-interaction

            # ----------------------------------------------
            #          Run pulumi in preview mode
            # ----------------------------------------------

            - name: Run pulumi preview
              uses: pulumi/actions@v3
              with:
                  command: preview
                  stack-name: dev
                  cloud-url: <s3://accrue-pulumi>

(poetry installs

pulumi

packages) I had to install

pulumi

packages via

pip

... again

# ----------------------------------------------
            #          install & configure poetry
            # ----------------------------------------------
            - name: Install Poetry
              uses: snok/install-poetry@v1.1.6
              with:
                  virtualenvs-create: true

            - name: Install dependencies
              run: |
                  poetry install --no-interaction

            # ----------------------------------------------
            #          Run pulumi in preview mode
            # ----------------------------------------------

            - name: Install pulumi via pip
              run: |
                  pip install pulumi
                  pip install pulumi-aws

            - name: Run pulumi preview
              uses: pulumi/actions@v3
              with:
                  command: preview
                  stack-name: dev
                  cloud-url: <s3://accrue-pulumi>

If I come up with a better way, I'll post it in the thread