Impossible to debug templates as a template author

[radu-matei]

I am updating a template I built a long time ago.

I have no idea what variable it's complaining about:

RUST_LOG=spin=trace spin new -t nextjs-ui deleteme
Description: Next.js UI
HTTP path: /...
2025-02-07T21:54:37.289707Z DEBUG spin: err=liquid: Unknown variable
  with:
    requested variable=member

Error: liquid: Unknown variable
  with:
    requested variable=member

How could I find out what variable it is referring to?

[lann]

Is it not...member?

[itowlson]

Could you share the repro case please? My reaction is the same as Lann's, but that seems so obvious that I assume you've already considered and rejected it. Without the actual template, therefore, it's hard to know what is being misreported.

(For what it's worth, my guess is that your app uses Handlebars or such like, contains code referring to e.g. {{ member }}, and does not escape the {{ ... }} (https://developer.fermyon.com/spin/v3/template-authoring#expression-syntax). If I guessed right, the template system would see the {{ member }} and look for a template variable named {{ member }}. But without the source code it's really hard to tell. Did I mention "guess"?)

I'll have a look and see if Liquid can give us locations - that would certainly help authors track down such problems.