Feat(dbt): Add dbt debug macro

[themisvaltinos]

This adds support for dbt's debug macro in a dbt project which opens an iPython debugger in the context of a macro

{% macro my_macro() %}
  {% set something_complex = my_complicated_macro() %}
  {{ debug() }}
{% endmacro %}

This is enabled both by using the dbt DBT_MACRO_DEBUGGING environment variable or the sqlmesh native: SQLMESH_DEBUG or running with --debug flag.

[erindru]

What does dbt do with a debug() call where DBT_MACRO_DEBUGGING is not set?

Does it just no-op, or does it throw an error? Because if it no-op's then wouldnt we need to always include it in the builtin globals and move the "is enabled?" check to within the implementation of debug()?

[themisvaltinos]

yes the latter, they have it under a conditional as well so that it throws an error (maybe since they warn "Do not deploy code to production that uses the debug macro" to ensure this is only for debugging. This is why I wanted to exactly mirror their approach to get the same result.

so running dbt when the flag is not set you get an error it is undefined:

06:44:48  Encountered an error:
Compilation Error in operation jaffle_shop-on-run-end-0 (./dbt_project.yml)
  'debug' is undefined

and for sqlmesh you'd get similarly the undefined error:

Error: An error occurred during rendering of the 'after_all' statements:
Could not render or parse jinja at 'None'.
'debug' is undefined