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

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

Attaching package: 'dplyr'

The following objects are masked from 'package:stats':

    filter, lag

The following objects are masked from 'package:base':

    intersect, setdiff, setequal, union

If you use data from the unvotes package, please cite the following:

Erik Voeten "Data and Analyses of Voting in the UN General Assembly" Routledge Handbook of International Organization, edited by Bob Reinalda (published May 27, 2013)
Warning: Problem with `mutate()` column `a2`.
ℹ `a2 = countrycode(item2, "country.name", "iso2c")`.
ℹ Some values were not matched unambiguously: Czechoslovakia, German Democratic Republic, Yemen Arab Republic, Yemen People's Republic, Yugoslavia, Zanzibar

Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)) :
  no font could be found for family "Arial"
Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y,  :
  no font could be found for family "Arial"
Quitting from lines 77-97 (united_nations.Rmd) 
Error: processing vignette 'united_nations.Rmd' failed with diagnostics:
polygon edge not found
--- failed re-building ‘united_nations.Rmd’

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

Error: Vignette re-building failed.
Execution halted