This should work:

```
---
format:
  customformat.lua: default
---
```

Instead we get a validation error. With `validate-yaml: false` everything works as expected.
cscheid
2022-09-30T19:19:43Z
cscheid
bug yaml-validation
v1.2
closed
support custom writers as format keys
https://github.com/quarto-dev/quarto-cli/issues/2687