Error in re-building vignettes:
  ...
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  The vignette engine knitr::rmarkdown is not available, because the rmarkdown package is not installed. Please install it.
Error in file(con, "r") : cannot open the connection
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  The vignette engine knitr::rmarkdown is not available, because the rmarkdown package is not installed. Please install it.

 *** caught segfault ***
address 0x33d6, cause 'memory not mapped'

Traceback:
 1: dev.off(dv)
 2: block_exec(params)
 3: call_block(x)
 4: process_group.block(group)
 5: process_group(group)
 6: withCallingHandlers(if (tangle) process_tangle(group) else process_group(group),     error = function(e) {        setwd(wd)        cat(res, sep = "\n", file = output %n% "")        message("Quitting from lines ", paste(current_lines(i),             collapse = "-"), " (", knit_concord$get("infile"),             ") ")    })
 7: process_file(text, output)
 8: knit(input, text = text, envir = envir, encoding = encoding,     quiet = quiet)
 9: knit2html(..., force_v1 = TRUE)
10: (if (grepl("\\.[Rr]md$", file)) knit2html_v1 else if (grepl("\\.[Rr]rst$",     file)) knit2pandoc else knit)(file, encoding = encoding,     quiet = quiet, envir = globalenv())
11: vweave(...)
12: engine$weave(file, quiet = quiet, encoding = enc)
13: doTryCatch(return(expr), name, parentenv, handler)
14: tryCatchOne(expr, names, parentenv, handlers[[1L]])
15: tryCatchList(expr, classes, parentenv, handlers)
16: tryCatch({    engine$weave(file, quiet = quiet, encoding = enc)    setwd(startdir)    find_vignette_product(name, by = "weave", engine = engine)}, error = function(e) {    stop(gettextf("processing vignette '%s' failed with diagnostics:\n%s",         file, conditionMessage(e)), domain = NA, call. = FALSE)})
17: buildVignettes(dir = "/data/gannet/ripley/R/packages/tests-devel/rstan.Rcheck/vign_test/rstan")
An irrecoverable exception occurred. R is aborting now ...