[CT-1409] [Bug] when there's a variable being called in a jinja block that is not defined in dbt_project.yml, there's an compile error

[bossnunta]

Is this a new bug in dbt-core?

• I believe this is a new bug in dbt-core
• I have searched the existing issues, and I could not find an existing issue for this bug

Current Behavior

Not 100% sure what about this code block causes the error. Possible there's a variable being called inside a jinja block
https://www.loom.com/share/eb8a9d3b57e24e588c5fa8b96e9d13cf

Expected Behavior

We shouldn't show any error here (?) -- see Loom for more info

Steps To Reproduce

1. Start with an existing project in the Cloud IDE
2. Choose any existing sql data model
3. add this block of code

{% if var('random_var_name') != [] %}
,
{{ var('random_var_name') | join (", ")}}

{% endif %}

4. Save file
5. Notice the error state from RPC
6. If you go into dbt_project.yml and define random_var_name, then the error goes away

Relevant log output

No response

Environment

- OS:
- Python:
- dbt:

Which database adapter are you using with dbt?

No response

Additional Context

No response

[jtcohen6]

After a little digging, there's more history here:

• Var does not exist exception not being caught #3320
• Fix: missing vars in disabled models fail compilation (#434) #1429
• Models that are disabled still fail compilation if they are missing vars #434

Big idea: At parse time, a missing var actually returns None (to avoid raising errors due to missing vars in disabled models). That works fine sometimes, but not if the variable is expected to support __iter__ type operations. Hence, 'NoneType' object is not iterable.

Going to re-label this one as a spike, to understand what's possible here as far as better UX.

[github-actions]

This issue has been marked as Stale because it has been open for 180 days with no activity. If you would like the issue to remain open, please comment on the issue or else it will be closed in 7 days.

[github-actions]

Although we are closing this issue as stale, it's not gone forever. Issues can be reopened if there is renewed community interest. Just add a comment to notify the maintainers.

[jatkins23]

Wanted to follow up that this is still not resolved if its possible to reopen