Cannot set query_tag through macro

Describe the bug

Trying to set query_tag in dbt_project.yml through a macro doesn’t work. Returns an error '<macro>' is undefined.

Steps To Reproduce

1. Create a macro which returns some text.
2. Use that macro as your query_tag, e.g:

models:
  query_tag: "{{ build_qtag('le_tag') }}" 

Expected behavior

The tag should be set from the macro… 😄

Screenshots and log output

Running with dbt=0.18.0
Encountered an error:
Compilation Error
  Could not render {{ build_qtag('le_tag') }}: 'build_qtag' is undefined

System information

Which database are you using dbt with?

• snowflake

The output of dbt --version:

installed version: 0.18.0
   latest version: 0.18.1

Your version of dbt is out of date! You can find instructions for upgrading here:
https://docs.getdbt.com/docs/installation

Plugins:
  - postgres: 0.18.0
  - redshift: 0.18.0
  - bigquery: 0.18.0
  - snowflake: 0.18.0

(Note: The same issue exists on 0.18.1)

The operating system you’re using:

• Docker, python:3.7

root@fa939f48db3d:/dbt# uname -a
Linux fa939f48db3d 5.8.0-7630-generic #32~1607010078~20.04~383a644-Ubuntu SMP Thu Dec 3 19:14:47 UTC 2 x86_64 GNU/Linux

The output of python --version: Python 3.7.9

[praktiskt]

I ran a small integration test (~100 models) and the only anomaly I could find was that the initial query (the one which actually sets the query_tag). I’ll let this run for a while and we’ll see what happens.

[jtcohen6]

We’ve seen issues where folks try to run alter session commands in a pre-hook, e.g. to change session parameters or the default timezone. Because dbt closes the connection once done, Snowflake may end the session, causing the model SQL to then run in a different session (with different session parameters, defaults, and tags).

One solution there is to use sql_header instead of pre-hook (docs), but sql_header does not support late-rendering, which is the thing you’re after here.

Could you try this approach, and check the Snowflake query history to confirm that your model query ran with the tag you expect?