[DOP-13156] Fix documentation build

.readthedocs.yaml

@@ -9,12 +9,16 @@ build:
     - libsasl2-dev
   jobs:
     post_create_environment:
-      - pip install poetry
-      - pip install sphinx-plantuml # remove after https://github.com/zqmillet/sphinx-plantuml/pull/4
-      - poetry config virtualenvs.create false
+      - $READTHEDOCS_VIRTUALENV_PATH/bin/python -m pip install poetry
+      - $READTHEDOCS_VIRTUALENV_PATH/bin/python -m pip install sphinx-plantuml # remove after https://github.com/zqmillet/sphinx-plantuml/pull/4
+      - $READTHEDOCS_VIRTUALENV_PATH/bin/python -m poetry config virtualenvs.create false
+      - $READTHEDOCS_VIRTUALENV_PATH/bin/python -m poetry config virtualenvs.prefer-active-python true
+      - $READTHEDOCS_VIRTUALENV_PATH/bin/python -m poetry debug info
     post_install:
-      - poetry install --no-root --all-extras --with docs --without dev,test
-      - poetry run python -m horizon.backend.export_openapi_schema docs/_static/openapi.json
+      - $READTHEDOCS_VIRTUALENV_PATH/bin/python -m poetry install --no-root --all-extras --with docs --without dev,test
+      - $READTHEDOCS_VIRTUALENV_PATH/bin/python -m poetry show -v
+      - $READTHEDOCS_VIRTUALENV_PATH/bin/python -m pip list -v
+      - $READTHEDOCS_VIRTUALENV_PATH/bin/python -m horizon.backend.export_openapi_schema docs/_static/openapi.json
 
 sphinx:
   configuration: docs/conf.py