Diagnosing a textConnection() Slowdown in R

Yihui Xie looks into an issue:

Running quarto render on a document with that single chunk took 35 seconds. The equivalent rmarkdown::render() finished in under half a second. As a side note in the issue, the reporter pinged me that the same problem existed in litedown. litedown is independent of both Quarto and knitr; it executes R code through xfun::record(). That is where I started looking.

Click through for the discovery process, explanation, and fix.