Error(s) in re-building vignettes:
  ...
--- re-building ‘a_1_getting_started.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
--- finished re-building ‘a_1_getting_started.Rmd’

--- re-building ‘a_2_mlrCPO_core.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
--- finished re-building ‘a_2_mlrCPO_core.Rmd’

--- re-building ‘a_3_all_CPOs.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
Quitting from lines 299-304 (a_3_all_CPOs.Rmd) 
Error: processing vignette 'a_3_all_CPOs.Rmd' failed with diagnostics:
unused argument (options = list(TRUE, TRUE, "markup", FALSE, NULL, TRUE, FALSE, "#>", TRUE, TRUE, "normalsize", "#F7F7F7", 0, "cache/", NULL, TRUE, NULL, FALSE, FALSE, "high", "asis", "default", "figure/", "png", NULL, 72, "png", 7, 7, "figure", NULL, NULL, "fig:", NULL, "", NULL, NULL, NULL, 1, TRUE, FALSE, 1, "controls,loop", TRUE, FALSE, TRUE, NULL, NULL, NULL, "R", FALSE, TRUE, TRUE, "unnamed-chunk-37", c("impdata %>>% cpoImputeConstant(10)", "getTaskData(missing.task %>>% cpoImputeMedian())", "# The specialised impute CPOs are:", 
"listCPO()[listCPO()$category == \"imputation\" & listCPO()$subcategory == \"specialised\",", "          c(\"name\", \"description\")]"), 504, 504, ""))
--- failed re-building ‘a_3_all_CPOs.Rmd’

--- re-building ‘a_4_custom_CPOs.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
--- finished re-building ‘a_4_custom_CPOs.Rmd’

--- re-building ‘z_1_getting_started_terse.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
--- finished re-building ‘z_1_getting_started_terse.Rmd’

--- re-building ‘z_2_mlrCPO_core_terse.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
--- finished re-building ‘z_2_mlrCPO_core_terse.Rmd’

--- re-building ‘z_3_all_CPOs_terse.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
--- finished re-building ‘z_3_all_CPOs_terse.Rmd’

--- re-building ‘z_4_custom_CPOs_terse.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
--- finished re-building ‘z_4_custom_CPOs_terse.Rmd’

SUMMARY: processing the following file failed:
  ‘a_3_all_CPOs.Rmd’

Error: Vignette re-building failed.
Execution halted