Error(s) in re-building vignettes:
--- re-building ‘bes-2015.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 ‘bes-2015.Rmd’

--- re-building ‘bes-2017.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 ‘bes-2017.Rmd’

--- re-building ‘census-11.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 ‘census-11.Rmd’

--- re-building ‘introduction.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.
Linking to GEOS 3.6.1, GDAL 2.1.3, PROJ 4.9.3

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

Downloading constituency data
PhantomJS not found. You can install it with webshot::install_phantomjs(). If it is installed, please make sure the phantomjs executable can be found via the PATH variable.
Warning in normalizePath(f2) :
  path[1]="webshot1120c561e20f1.png": No such file or directory
Warning in file(con, "rb") :
  cannot open file 'webshot1120c561e20f1.png': No such file or directory
Quitting from lines 65-110 (introduction.Rmd) 
Error: processing vignette 'introduction.Rmd' failed with diagnostics:
cannot open the connection
--- failed re-building ‘introduction.Rmd’

--- re-building ‘mapping-local-authorities.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.
Linking to GEOS 3.6.1, GDAL 2.1.3, PROJ 4.9.3

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

Joining, by = "name"
Warning: Column `majority_party`/`party_name` joining character vector and factor, coercing into character vector
PhantomJS not found. You can install it with webshot::install_phantomjs(). If it is installed, please make sure the phantomjs executable can be found via the PATH variable.
Warning in normalizePath(f2) :
  path[1]="webshot1121a44e32c24.png": No such file or directory
Warning in file(con, "rb") :
  cannot open file 'webshot1121a44e32c24.png': No such file or directory
Quitting from lines 18-66 (mapping-local-authorities.Rmd) 
Error: processing vignette 'mapping-local-authorities.Rmd' failed with diagnostics:
cannot open the connection
--- failed re-building ‘mapping-local-authorities.Rmd’

--- re-building ‘using-cartograms.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.
Linking to GEOS 3.6.1, GDAL 2.1.3, PROJ 4.9.3

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

Warning: Column `winner_17`/`party_name` joining factors with different levels, coercing to character vector
Warning in RGEOSMiscFunc(spgeom, byid, "rgeos_area") :
  Spatial object is not projected; GEOS expects planar coordinates
Warning in RGEOSMiscFunc(spgeom, byid, "rgeos_area") :
  Spatial object is not projected; GEOS expects planar coordinates
Warning in RGEOSMiscFunc(spgeom, byid, "rgeos_area") :
  Spatial object is not projected; GEOS expects planar coordinates
Warning in RGEOSMiscFunc(spgeom, byid, "rgeos_area") :
  Spatial object is not projected; GEOS expects planar coordinates
Mean size error for iteration 1: 1.84531493905147
Warning in RGEOSMiscFunc(spgeom, byid, "rgeos_area") :
  Spatial object is not projected; GEOS expects planar coordinates
Warning in RGEOSMiscFunc(spgeom, byid, "rgeos_area") :
  Spatial object is not projected; GEOS expects planar coordinates
Mean size error for iteration 2: 1.58187122064144
Warning in RGEOSMiscFunc(spgeom, byid, "rgeos_area") :
  Spatial object is not projected; GEOS expects planar coordinates
Warning in RGEOSMiscFunc(spgeom, byid, "rgeos_area") :
  Spatial object is not projected; GEOS expects planar coordinates
Mean size error for iteration 3: 1.38843407779149
Warning in RGEOSMiscFunc(spgeom, byid, "rgeos_area") :
  Spatial object is not projected; GEOS expects planar coordinates
Warning in RGEOSMiscFunc(spgeom, byid, "rgeos_area") :
  Spatial object is not projected; GEOS expects planar coordinates
Mean size error for iteration 4: 1.25207736302913
Warning in RGEOSMiscFunc(spgeom, byid, "rgeos_area") :
  Spatial object is not projected; GEOS expects planar coordinates
Warning in RGEOSMiscFunc(spgeom, byid, "rgeos_area") :
  Spatial object is not projected; GEOS expects planar coordinates
Mean size error for iteration 5: 1.16058515692674
PhantomJS not found. You can install it with webshot::install_phantomjs(). If it is installed, please make sure the phantomjs executable can be found via the PATH variable.
Warning in normalizePath(f2) :
  path[1]="webshot11228274bbb5b.png": No such file or directory
Warning in file(con, "rb") :
  cannot open file 'webshot11228274bbb5b.png': No such file or directory
Quitting from lines 25-82 (using-cartograms.Rmd) 
Error: processing vignette 'using-cartograms.Rmd' failed with diagnostics:
cannot open the connection
--- failed re-building ‘using-cartograms.Rmd’

SUMMARY: processing the following files failed:
  ‘introduction.Rmd’ ‘mapping-local-authorities.Rmd’
  ‘using-cartograms.Rmd’

Error: Vignette re-building failed.
Execution halted