Running examples in ‘rchallenge-Ex.R’ failed
The error most likely occurred in:

> ### Name: icon
> ### Title: HTML code for icons.
> ### Aliases: icon
> 
> ### ** Examples
> 
> rmd <- '
+ ```{r}
+ library(rchallenge)
+ ```
+ <link rel="stylesheet" 
+  href="https://maxcdn.bootstrapcdn.com/font-awesome/4.6.3/css/font-awesome.min.css">
+ `r icon("fa-user")`
+ `r icon("fa-user fa-lg")`
+ `r icon("fa-user fa-2x")`
+ `r icon("fa-user fa-3x")`
+ `r icon("fa-user fa-3x fa-border")`
+ '
> file <- tempfile()
> cat(rmd, file=file)
> writeLines(readLines(file))

```{r}
library(rchallenge)
```
<link rel="stylesheet" 
 href="https://maxcdn.bootstrapcdn.com/font-awesome/4.6.3/css/font-awesome.min.css">
`r icon("fa-user")`
`r icon("fa-user fa-lg")`
`r icon("fa-user fa-2x")`
`r icon("fa-user fa-3x")`
`r icon("fa-user fa-3x fa-border")`
> rmarkdown::render(file)
/usr/local/bin/pandoc +RTS -K512m -RTS file107f276efaa63.utf8.md --to html4 --from markdown+autolink_bare_uris+tex_math_single_backslash+smart --output file107f276efaa63.html --email-obfuscation none --self-contained --standalone --section-divs --template /Volumes/Builds/packages/high-sierra-x86_64/Rlib/4.0/rmarkdown/rmd/h/default.html --no-highlight --variable highlightjs=1 --variable 'theme:bootstrap' --include-in-header /var/folders/08/nc4f1s3x1jqd9ln5mnvrqzqh0000gp/T//RtmpD2yDUL/rmarkdown-str107f2709b8695.html --mathjax --variable 'mathjax-url:https://mathjax.rstudio.com/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML' --lua-filter /Volumes/Builds/packages/high-sierra-x86_64/Rlib/4.0/rmarkdown/rmd/lua/pagebreak.lua --lua-filter /Volumes/Builds/packages/high-sierra-x86_64/Rlib/4.0/rmarkdown/rmd/lua/latex-div.lua 
dyld: lazy symbol binding failed: Symbol not found: ____chkstk_darwin
  Referenced from: /usr/local/bin/pandoc (which was built for Mac OS X 10.15)
  Expected in: /usr/lib/libSystem.B.dylib

dyld: Symbol not found: ____chkstk_darwin
  Referenced from: /usr/local/bin/pandoc (which was built for Mac OS X 10.15)
  Expected in: /usr/lib/libSystem.B.dylib

Error: pandoc document conversion failed with error 6
Execution halted