Error(s) in re-building vignettes:
--- re-building ‘cartograflow_general.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 3.7.2, GDAL 2.4.2, PROJ 5.2.0

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 in st_centroid.sf(.) :
  st_centroid assumes attributes are constant over geometries of x
Warning in st_centroid.sf(.) :
  st_centroid assumes attributes are constant over geometries of x
Warning in arrows(mgp_flow$Xi, mgp_flow$Yi, mgp_flow$Xj, mgp_flow$Yj, length = a.length,  :
  zero-length arrow is of indeterminate angle and so skipped
Warning in arrows(mgp_flow$Xi, mgp_flow$Yi, mgp_flow$Xj, mgp_flow$Yj, length = a.length,  :
  zero-length arrow is of indeterminate angle and so skipped
Warning in arrows(mgp_flow$Xi, mgp_flow$Yi, mgp_flow$Xj, mgp_flow$Yj, length = a.length,  :
  zero-length arrow is of indeterminate angle and so skipped
Warning in arrows(mgp_flow$Xi, mgp_flow$Yi, mgp_flow$Xj, mgp_flow$Yj, length = a.length,  :
  zero-length arrow is of indeterminate angle and so skipped
Warning in arrows(mgp_flow$Xi, mgp_flow$Yi, mgp_flow$Xj, mgp_flow$Yj, length = a.length,  :
  zero-length arrow is of indeterminate angle and so skipped
Warning in arrows(mgp_flow$Xi, mgp_flow$Yi, mgp_flow$Xj, mgp_flow$Yj, length = a.length,  :
  zero-length arrow is of indeterminate angle and so skipped
Warning in arrows(mgp_flow$Xi, mgp_flow$Yi, mgp_flow$Xj, mgp_flow$Yj, length = a.length,  :
  zero-length arrow is of indeterminate angle and so skipped
Warning in arrows(mgp_flow$Xi, mgp_flow$Yi, mgp_flow$Xj, mgp_flow$Yj, length = a.length,  :
  zero-length arrow is of indeterminate angle and so skipped
Warning in arrows(mgp_flow$Xi, mgp_flow$Yi, mgp_flow$Xj, mgp_flow$Yj, length = a.length,  :
  zero-length arrow is of indeterminate angle and so skipped
Warning in arrows(mgp_flow$Xi, mgp_flow$Yi, mgp_flow$Xj, mgp_flow$Yj, length = a.length,  :
  zero-length arrow is of indeterminate angle and so skipped
Warning in arrows(mgp_flow$Xi, mgp_flow$Yi, mgp_flow$Xj, mgp_flow$Yj, length = a.length,  :
  zero-length arrow is of indeterminate angle and so skipped
Warning in arrows(mgp_flow$Xi, mgp_flow$Yi, mgp_flow$Xj, mgp_flow$Yj, length = a.length,  :
  zero-length arrow is of indeterminate angle and so skipped
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  zero-length arrow is of indeterminate angle and so skipped
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  zero-length arrow is of indeterminate angle and so skipped
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  zero-length arrow is of indeterminate angle and so skipped
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  zero-length arrow is of indeterminate angle and so skipped
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  zero-length arrow is of indeterminate angle and so skipped
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  zero-length arrow is of indeterminate angle and so skipped
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  zero-length arrow is of indeterminate angle and so skipped
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  zero-length arrow is of indeterminate angle and so skipped
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  zero-length arrow is of indeterminate angle and so skipped
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  zero-length arrow is of indeterminate angle and so skipped
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  zero-length arrow is of indeterminate angle and so skipped
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  zero-length arrow is of indeterminate angle and so skipped
Warning: Use of `x$flowcum` is discouraged. Use `flowcum` instead.
Warning: Use of `x$linkcum` is discouraged. Use `linkcum` instead.
Warning: Use of `x$flowcum` is discouraged. Use `flowcum` instead.
Warning: Use of `x$flowcum` is discouraged. Use `flowcum` instead.
Warning in normalizePath(f2) :
  path[1]="webshot155f45994e035.png": No such file or directory
Warning in file(con, "rb") :
  cannot open file 'webshot155f45994e035.png': No such file or directory
Quitting from lines 353-360 (cartograflow_general.Rmd) 
Error: processing vignette 'cartograflow_general.Rmd' failed with diagnostics:
cannot open the connection
--- failed re-building ‘cartograflow_general.Rmd’

SUMMARY: processing the following file failed:
  ‘cartograflow_general.Rmd’

Error: Vignette re-building failed.
Execution halted