Error(s) in re-building vignettes:
  ...
--- re-building ‘CAST-intro.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.
CAST                   package:CAST                    R Documentation

'_c_a_r_e_t' _A_p_p_l_i_c_a_t_i_o_n_s _f_o_r _S_p_a_t_i_a_l-_T_e_m_p_o_r_a_l _M_o_d_e_l_s

_D_e_s_c_r_i_p_t_i_o_n:

     Supporting functionality to run 'caret' with spatial or
     spatial-temporal data. 'caret' is a frequently used package for
     model training and prediction using machine learning. This package
     includes functions to improve spatial-temporal modelling tasks
     using 'caret'. It prepares data for Leave-Location-Out and
     Leave-Time-Out cross-validation which are target-oriented
     validation strategies for spatial-temporal models. To decrease
     overfitting and improve model performances, the package implements
     a forward feature selection that selects suitable predictor
     variables in view to their contribution to the target-oriented
     performance.

_D_e_t_a_i_l_s:

     'caret' Applications for Spatio-Temporal models

_A_u_t_h_o_r(_s):

     Hanna Meyer, Christoph Reudenbach, Marvin Ludwig, Thomas Nauss
     _Maintainer:_ Hanna Meyer <email: hanna.meyer@geo.uni-marburg.de>


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]="webshot66f76f6675c1.png": No such file or directory
Warning in file(con, "rb") :
  cannot open file 'webshot66f76f6675c1.png': No such file or directory
Quitting from lines 65-73 (CAST-intro.Rmd) 
Error: processing vignette 'CAST-intro.Rmd' failed with diagnostics:
cannot open the connection
--- failed re-building ‘CAST-intro.Rmd’

SUMMARY: processing the following file failed:
  ‘CAST-intro.Rmd’

Error: Vignette re-building failed.
Execution halted