Use of eval RMarkdown chunk option

[jl5000]

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Description

I have a pipeline where I am rendering an RMarkdown document which has chunks that are evaluated based on variables (targets). I have two issues with the current functionality:

1. Errors are displayed before the pipeline runs (but it still runs successfully - except the issue below)
2. It does not recognise target dependencies contained within chunks that use the eval option.

Reprex below:

library(tarchetypes)
#> Warning: package 'tarchetypes' was built under R version 4.4.3

lines1 <- c(
  "---",
  "title: report",
  "output_format: html_document",
  "---",
  "",
  "```{r}",
  "x <- TRUE",
  "```",
  "",
  "```{r}",
  "tar_load(data1)",
  "```",
  "",
  "```{r, eval=x}",
  "tar_read(data2)",
  "```"
)

report1 <- tempfile()
writeLines(lines1, report1)

tar_knitr_deps(report1)

#> Error in eval(x, envir = envir) : object 'x' not found
#> [1] "data1"

^{Created on 2025-12-11 with reprex v2.1.1}

[wlandau]

Dependencies of an R Markdown document in a targets pipeline must all be declared with tar_read() or tar_load().

tar_knitr_deps() calls knit::knit(tangle = TRUE), which unfortunately throws an error if the eval chunk option is set to an undefined variable like x.

[jl5000]

Ah ok, so the error messages aren't a tarchetypes issue. I can easily find a way around the second issue by pre-loading all the targets required before using them, so that part is resolvable - I'm guessing that's an issue with the way knitr purls a document.