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

> ### Name: publish
> ### Title: Render your challenge R Markdown script to a HTML page.
> ### Aliases: publish
> 
> ### ** Examples
> 
> path <- tempdir()
> wd <- setwd(path)
> new_challenge()
New challenge installed in: "D:\temp\RtmpktEGFA"
Next steps to complete the installation:
1. Replace the data files in the "data" subdirectory.
2. Replace the baseline predictions in "submissions/baseline".
3. Customize the template R Markdown file "challenge.rmd" as needed.
4. Create and share subdirectories in "submissions" for each team:
    rchallenge::new_team("team_foo", "team_bar", path=".", submissions_dir="submissions")
5. Render the HTML page:
    rchallenge::publish("./challenge.rmd")
6. Give the URL to "challenge.html" to the participants.
7. Automate the updates of the webpage.
   On Windows systems, you can use the Task Scheduler to create a new task with a "Start a program" action with the settings:   - Program/script: Rscript.exe
   - options: -e rchallenge::publish('D:\temp\RtmpktEGFA\challenge.rmd')
> outdir = tempdir()
> publish(output_dir = outdir, output_options = list(self_contained = FALSE))


processing file: challenge.rmd
Error in namespaceExport(ns, exports) : 
  undefined exports: %s!=%, %s!==%, %s+%, %s<%, %s<=%, %s==%, %s===%, %s>%, %s>=%, %stri!=%, %stri!==%, %stri+%, %stri<%, %stri<=%, %stri==%, %stri===%, %stri>%, %stri>=%, stri_datetime_add<-, stri_sub<-, stri_subset<-, stri_subset_charclass<-, stri_subset_coll<-, stri_subset_fixed<-, stri_subset_regex<-, stri_c, stri_c_list, stri_cmp, stri_cmp_eq, stri_cmp_equiv, stri_cmp_ge, stri_cmp_gt, stri_cmp_le, stri_cmp_lt, stri_cmp_neq, stri_cmp_nequiv, stri_compare, stri_conv, stri_count, stri_count_boundaries, stri_count_charclass, stri_count_coll, stri_count_fixed, stri_count_regex, stri_count_words, stri_datetime_add, stri_datetime_create, stri_datetime_fields, stri_datetime_format, stri_datetime_fstr, stri_datetime_now, stri_datetime_parse, stri_datetime_symbols, stri_detect, stri_detect_charclass, stri_detect_coll, stri_detect_fixed, stri_detect_regex, stri_dup, stri_duplicated, stri_duplicated_any, stri_enc_detect, stri_enc_detect2, stri_enc_fromutf32, stri_enc_get, stri_enc_inf
Calls: publish ... tryCatch -> tryCatchList -> tryCatchOne -> <Anonymous>
Execution halted