Error when pipeline.yaml file has indentation issue

[neelasha23]

Pipeline.yaml had some indentation inconsistency in one of the entries, however the error that came up was related to placeholders:

ploomber.exceptions.DAGSpecInitializationError: Failed to initialize spec. It looks like you're using placeholders (i.e. {{placeholder}}). Make sure values are enclosed in parentheses (e.g. key: "{{placeholder}}"). Original parser error:
                  
                  mapping values are not allowed here
                     in "<unicode string>", line 14, column 11:
                             name: clean

[edublancas]

do remember the pipeline.yaml contents so we can reproduce it?

[neelasha23]

Yes it was something like:

meta:
  extract_product: False

tasks:
  - source: raw.py
    name: raw
    product: {'nb': '{{path.products}}/data.ipynb', 'data': '{{path.products}}/data.csv'}

  - source: clean_one.py
     name: clean-1
     product: {'nb': '{{path.products}}/clean_one.ipynb', 'data': '{{path.products}}/clean_one.csv'}

  - source: clean_two.py
    name: clean-2
    product: { 'nb': '{{path.products}}/clean_two.ipynb', 'data': '{{path.products}}/clean_two.csv' }

  - source: plot.py
    name: plot
    product: {'nb': '{{path.products}}/plot.ipynb'}

(Indentation is more in name and product keys of clean_one)

If we validate this on a yaml validator the error is (<unknown>): mapping values are not allowed in this context at line 10 column 10. So maybe if this error comes up we can throw error Possible indentation issue

[edublancas]

Yeah, good point. So the idea with the "It looks like you're using placeholders..." was to provide a more user-friendly error message. But the scenario you encounter is a false positive. I think I'm only validating the error type and that the pipeline.yaml contains {{ and }}, but I guess we should also see if there's any other think we should validate before showing that message.

Regarding your suggestion, yes. I think the original "mapping values are not allowed..." message is confusing and we should add something like "you may have indentation issues"