Error in re-building vignettes:
  ...
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
Warning in engine$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 2.2.0, proj.4 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 GitHub repo tidyverse/ggplot2@master
from URL https://api.github.com/repos/tidyverse/ggplot2/zipball/master
Installing ggplot2
Downloading GitHub repo hadley/scales@master
from URL https://api.github.com/repos/hadley/scales/zipball/master
Installing scales
'/home/ripley/R/gcc/bin/R' --no-site-file --no-environ --no-save  \
  --no-restore --quiet CMD INSTALL  \
  '/tmp/RtmprpaO64/devtools71d53cb342c/hadley-scales-6db7b6f'  \
  --library='/home/ripley/R/Lib32' --install-tests 

* installing *source* package ‘scales’ ...
** libs
/opt/csw//bin/g++ -I/home/ripley/R/gcc/include -DNDEBUG  -I"/home/ripley/R/Lib32/Rcpp/include" -I/opt/csw/include -I/usr/local/include   -fPIC  -O2  -c RcppExports.cpp -o RcppExports.o
/opt/csw//bin/g++ -I/home/ripley/R/gcc/include -DNDEBUG  -I"/home/ripley/R/Lib32/Rcpp/include" -I/opt/csw/include -I/usr/local/include   -fPIC  -O2  -c colors.cpp -o colors.o
/opt/csw//bin/g++ -shared -L/usr/local/lib -L/opt/csw/lib -o scales.so RcppExports.o colors.o
installing to /home/ripley/R/Lib32/scales/libs
** R
** tests
** preparing package for lazy loading
** help
Loading required package: scales
*** installing help indices
** building package indices
** testing if installed package can be loaded
* DONE (scales)
'/home/ripley/R/gcc/bin/R' --no-site-file --no-environ --no-save  \
  --no-restore --quiet CMD INSTALL  \
  '/tmp/RtmprpaO64/devtools71d5331e1b8d/tidyverse-ggplot2-32e699e'  \
  --library='/home/ripley/R/Lib32' --install-tests 

* installing *source* package ‘ggplot2’ ...
** R
** data
*** moving datasets to lazyload DB
** inst
** tests
** preparing package for lazy loading
** help
*** installing help indices
*** copying figures
** building package indices
** installing vignettes
** testing if installed package can be loaded
* DONE (ggplot2)
Downloading MP data
Downloading constituency data
Warning: Column `party_id` joining character vector and factor, coercing into character vector
Downloading MP data
Downloading constituency data
Warning: Column `party_id` 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]="./webshot71d569b63734.png": No such file or directory
Warning in file(con, "rb") :
  cannot open file './webshot71d569b63734.png': No such file or directory
Quitting from lines 100-145 (introduction.Rmd) 
Error: processing vignette 'introduction.Rmd' failed with diagnostics:
cannot open the connection
Execution halted