Error(s) in re-building vignettes:
--- re-building ‘geom_fan.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) not available. Falling back to R Markdown v1.
Quitting from lines 59-62 (geom_fan.Rmd) 
Error: processing vignette 'geom_fan.Rmd' failed with diagnostics:
polygon edge not found
--- failed re-building ‘geom_fan.Rmd’

--- re-building ‘ggfan_stan.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) not available. Falling back to R Markdown v1.
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  no font could be found for family "Arial"
Quitting from lines 107-108 (ggfan_stan.Rmd) 
Error: processing vignette 'ggfan_stan.Rmd' failed with diagnostics:
polygon edge not found
--- failed re-building ‘ggfan_stan.Rmd’

SUMMARY: processing the following files failed:
  ‘geom_fan.Rmd’ ‘ggfan_stan.Rmd’

Error: Vignette re-building failed.
Execution halted