Error in re-building vignettes:
  ...
randomForest 4.6-14
Type rfNews() to see new features/changes/bug fixes.
Warning: Using alpha for a discrete variable is not advised.

 *** caught segfault ***
address 0x6a63, cause 'memory not mapped'

Traceback:
 1: FUN(X[[i]], ...)
 2: lapply(aesthetics[new_aesthetics], rlang::eval_tidy, data = data)
 3: scales_add_defaults(plot$scales, data, aesthetics, plot$plot_env)
 4: f(..., self = self)
 5: l$compute_aesthetics(d, plot)
 6: f(l = layers[[i]], d = data[[i]])
 7: by_layer(function(l, d) l$compute_aesthetics(d, plot))
 8: ggplot_build.ggplot(p)
 9: ggplot_build(p)
10: ggplot_gtable(ggplot_build(p))
11: plot_gtable(p)
12: ggmatrix_gtable(x, ...)
13: print.ggmatrix(x)
14: print(x)
15: normal_print(x)
16: knit_print.default(x, ...)
17: knit_print(x, ...)
18: withVisible(knit_print(x, ...))
19: fun(x, options = options)
20: value_fun(ev$value, ev$visible)
21: withVisible(value_fun(ev$value, ev$visible))
22: withCallingHandlers(withVisible(value_fun(ev$value, ev$visible)),     warning = wHandler, error = eHandler, message = mHandler)
23: handle(pv <- withCallingHandlers(withVisible(value_fun(ev$value,     ev$visible)), warning = wHandler, error = eHandler, message = mHandler))
24: evaluate_call(expr, parsed$src[[i]], envir = envir, enclos = enclos,     debug = debug, last = i == length(out), use_try = stop_on_error !=         2L, keep_warning = keep_warning, keep_message = keep_message,     output_handler = output_handler, include_timing = include_timing)
25: evaluate::evaluate(...)
26: evaluate(code, envir = env, new_device = FALSE, keep_warning = !isFALSE(options$warning),     keep_message = !isFALSE(options$message), stop_on_error = if (options$error &&         options$include) 0L else 2L, output_handler = knit_handlers(options$render,         options))
27: in_dir(input_dir(), evaluate(code, envir = env, new_device = FALSE,     keep_warning = !isFALSE(options$warning), keep_message = !isFALSE(options$message),     stop_on_error = if (options$error && options$include) 0L else 2L,     output_handler = knit_handlers(options$render, options)))
28: block_exec(params)
29: call_block(x)
30: process_group.block(group)
31: process_group(group)
32: withCallingHandlers(if (tangle) process_tangle(group) else process_group(group),     error = function(e) {        setwd(wd)        cat(res, sep = "\n", file = output %n% "")        message("Quitting from lines ", paste(current_lines(i),             collapse = "-"), " (", knit_concord$get("infile"),             ") ")    })
33: process_file(text, output)
34: knitr::knit(knit_input, knit_output, envir = envir, quiet = quiet,     encoding = encoding)
35: rmarkdown::render(file, encoding = encoding, quiet = quiet, envir = globalenv())
36: vweave_rmarkdown(...)
37: engine$weave(file, quiet = quiet, encoding = enc)
38: doTryCatch(return(expr), name, parentenv, handler)
39: tryCatchOne(expr, names, parentenv, handlers[[1L]])
40: tryCatchList(expr, classes, parentenv, handlers)
41: tryCatch({    engine$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)})
42: buildVignettes(dir = "/home/hornik/tmp/R.check/r-devel-gcc/Work/PKGS/randomForestExplainer.Rcheck/vign_test/randomForestExplainer")
An irrecoverable exception occurred. R is aborting now ...
Segmentation fault