ERROR: Error executing 'Rscript'

[royfrancis]

Description

I have a template quarto document like this with no code chunks:

---
title: "Test"
format: html

knitr:
  opts_chunk:
    results: hold
---

Running quarto render index.qmd returns this error:

▸ quarto render index.qmd

ERROR: Error executing 'Rscript': Not a directory (os error 20)

Unable to locate an installed version of R.
Install R from https://cloud.r-project.org/

Removing the knitr argument makes it work. There is no R installation. I understand that knitr is an rmarkdown argument, but it is included as a template option in case an R chunk is included. In this document, there are no R code chunks to actually use that argument. Is this the expected behaviour?

▸ quarto --version
1.3.433

[cscheid]

I believe that if we see options in knitr:, we set the engine to knitr by default. This is a bit confusing, but it's there (I believe) to reduce the differences between markdown and quarto.

I do agree that it has unfortunate consequences. If I understand the situation correctly, the presence of a top-level knitr key in YAMLM metadata stops our engine inference code from firing. You could change this behavior with engine: markdown, but then you will not get knitr to run unless there's an explicit engine: knitr in the document, which is also unlikely to be what you want.

I can't think of a good solution here, sadly.

[cderv]

if we see options in knitr:, we set the engine to knitr by default (...) but it's there (I believe) to reduce the differences between markdown and quarto.

I wondered the same. I think we set engine when we see knitr: because if a document provides such options, then it is meant to be rendered with R engine.

You could change this behavior with engine: markdown

We resolve knitr: field before looking at execute engine in markdownExecutionEngine() so this won't work.

Our detection is:

• look for known engine name in YAML top field
• otherwise, look if engine: field is set
• otherwise, guess from document content with cells language.
• If no engine found for detected language, defaults to markdown

I don't know why we do the first exactly 🤔 it would probably have been fine without, but now it would break changing this I guess