Package suggested but not available for checking: ‘maptools’
Error(s) in re-building vignettes:
  ...
--- re-building ‘riverplot-gallery.rmd’ using rmarkdown

Quitting from lines 78-104 [export2] (riverplot-gallery.rmd)
Error: processing vignette 'riverplot-gallery.rmd' failed with diagnostics:
there is no package called 'maptools'
--- failed re-building ‘riverplot-gallery.rmd’

SUMMARY: processing the following file failed:
  ‘riverplot-gallery.rmd’

Error: Vignette re-building failed.
Execution halted
Package suggested but not available for checking: ‘maptools’
Error(s) in re-building vignettes:
  ...
--- re-building ‘riverplot-gallery.rmd’ using rmarkdown

Quitting from lines 78-104 [export2] (riverplot-gallery.rmd)
Error: processing vignette 'riverplot-gallery.rmd' failed with diagnostics:
there is no package called 'maptools'
--- failed re-building ‘riverplot-gallery.rmd’

SUMMARY: processing the following file failed:
  ‘riverplot-gallery.rmd’

Error: Vignette re-building failed.
Execution halted
Package suggested but not available for checking: ‘maptools’
Error(s) in re-building vignettes:
--- re-building ‘riverplot-gallery.rmd’ using rmarkdown

Quitting from lines 78-104 [export2] (riverplot-gallery.rmd)
Error: processing vignette 'riverplot-gallery.rmd' failed with diagnostics:
there is no package called 'maptools'
--- failed re-building ‘riverplot-gallery.rmd’

SUMMARY: processing the following file failed:
  ‘riverplot-gallery.rmd’

Error: Vignette re-building failed.
Execution halted
Package suggested but not available for checking: ‘maptools’
Error(s) in re-building vignettes:
--- re-building ‘riverplot-gallery.rmd’ using rmarkdown

Quitting from lines 78-104 [export2] (riverplot-gallery.rmd)
Error: processing vignette 'riverplot-gallery.rmd' failed with diagnostics:
there is no package called 'maptools'
--- failed re-building ‘riverplot-gallery.rmd’

SUMMARY: processing the following file failed:
  ‘riverplot-gallery.rmd’

Error: Vignette re-building failed.
Execution halted