KeyError with environment variable

Question

Hello it appears that creating a flow deployment fails when I set an env var as the default value for a task input parameter I assume that s because the environment that creates the flow deployment GitHub Actions Runner doesn t have that env var set Is this a bug I feel like I should be able to create and apply the deployment with no issues Examples in thread

Samuel Kohlleffel · Answer

Deployment works

Samuel Kohlleffel · Answer

Deployment fails

Peyton Runyan · Answer

Is there a stack trace that came with the error

Peyton Runyan · Answer

And when you say deployment fails do you mean the build step fails Or the deployment fails when you run it If I ve got more details on the error I should be able to get a better feel for it

Peyton Runyan · Answer

Ah I m actually in the middle of a PR that will fix the `ScriptError` messages so that you get a more useful error message Just reproduced this You get a `KeyError` It runs just fine if the environment variable is present

Peyton Runyan · Answer

If you want to get an environment variable and not throw a `KeyError` when it s not present you need to use `os getenv lt MY VAR gt ` which functions the same ways a `dict get ` This applies to all of python not just prefect

Samuel Kohlleffel · Answer

Ah OK Will do Thanks for the help

Samuel Kohlleffel · Answer

< Peyton Runyan> Is there a way to ensure `Deployment build from flow ` throws a Python exception when any error occurs Right now we just get a log message showing the generic error but the script continues to run as if no error occurred

Peyton Runyan · Answer

Can you past the whole error trace

Samuel Kohlleffel · Answer

Here s the error log Unfortunately a trace isn t logged out when an error occurs during `Deployment build from flow` ```13 46 24 407 | ERROR | root Script at workspaces nimbus orchestration flows hvr alerting hvr alerting py encountered an exception``` For context we deploy our flows during a CI job GitHub Actions Because the script that builds the flow deployments and pushes them to Prefect Cloud doesn t throw an error we could in theory have a failed deployment but our GH Action won t fail and we won t know about it Prefect won t update create that deployment with the error which is an issue especially if we don t know about it

Peyton Runyan · Answer

I m gonna need a hand reproducing this Can you get a minimum example locally that results in this same situation that I can copy and try out

Samuel Kohlleffel · Answer

So it turns out it wasn t an issue on y alls end I just realized we re handling errors of `load flow from script` incorrectly Sorry to waste your time I really appreciate the help though I would ve never found the issue had you not requested a working example

Peyton Runyan · Answer

No worries man

Peyton Runyan · Answer

Glad you got it figured out slightly smiling face