Hi again!
This is a short follow-up to the latest announcement:
to clarify what being explicit about your Prefect version means in practice.
Please make sure to follow the instructions below to ensure that, as we transition to Prefect 2.0 being the default version of Prefect starting on Wednesday, 27th of July, your flows using Prefect 1.0 keep working or at least keep failing successfully.
Pip and Conda
When installing Prefect using pip or conda, please specify the exact Prefect version you need to avoid surprises as we’re going to change the default version to the latest Prefect 2.0 release on Wednesday, 27th of July 
This explicit command will install the latest Prefect 1.0 version, which is 1.2.5 as of today:
pip install prefect==1.2.5
Installing Prefect with an implicit version will install Prefect 2.0, which will break your existing flows if they have been written using Prefect 1.0:
pip install prefect
Docker image tags
When working with Docker images in your run configuration or custom Dockerfiles, it’s best to use an explicit tag indicating the right Prefect version you need:
This is the most recent Prefect 1.0 Docker image tag for Python 3.9, which is 1.2.5 as of today:
prefecthq/prefect:1.2.5-python3.9
Using an implicit, i.e., the latest Docker image tag for Python 3.9 (or any other Python version) will still leverage Prefect 1.0 as the default to avoid breaking flows for others but it’s still recommended to pin the image tag you need:
prefecthq/prefect:latest-python3.9
For more info on Docker image versions, check out:
The most recent version of Prefect 2.0 are images:
- prefecthq:prefect:2-python3.10
- prefecthq:prefect:2-python3.9
- prefecthq:prefect:2-python3.8
- prefecthq:prefect:2-python3.7
Latest-tagged images:
https://hub.docker.com/r/prefecthq/prefect/tags?page=1&name=latest
If you have any questions about it, please reach out.