Error(s) in re-building vignettes:
--- re-building 'pavo-1-overview.Rmd' using rmarkdown
--- finished re-building 'pavo-1-overview.Rmd'

--- re-building 'pavo-2-importing_processing.Rmd' using rmarkdown
Welcome to pavo 2! Take a look at the latest features (and update your bibliography) in our recent publication: Maia R., Gruson H., Endler J. A., White T. E. (2019) pavo 2: new tools for the spectral and spatial analysis of colour in R. Methods in Ecology and Evolution, Early View.
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Quitting from lines 422-423 (pavo-2-importing_processing.Rmd) 
Error: processing vignette 'pavo-2-importing_processing.Rmd' failed with diagnostics:
Magick: UnableToOpenBlob `D:\temp\RtmpOsJPGo\RLIBS_ba083df06097\pavo\testdata\images': Permission denied @ error/blob.c/OpenBlob/2701
--- failed re-building 'pavo-2-importing_processing.Rmd'

--- re-building 'pavo-3-analysing.Rmd' using rmarkdown
Welcome to pavo 2! Take a look at the latest features (and update your bibliography) in our recent publication: Maia R., Gruson H., Endler J. A., White T. E. (2019) pavo 2: new tools for the spectral and spatial analysis of colour in R. Methods in Ecology and Evolution, Early View.
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Quitting from lines 741-742 (pavo-3-analysing.Rmd) 
Error: processing vignette 'pavo-3-analysing.Rmd' failed with diagnostics:
Magick: UnableToOpenBlob `D:\temp\RtmpOsJPGo\RLIBS_ba083df06097\pavo\testdata\images': Permission denied @ error/blob.c/OpenBlob/2701
--- failed re-building 'pavo-3-analysing.Rmd'

--- re-building 'pavo-4-spectraldesc.Rmd' using rmarkdown
--- finished re-building 'pavo-4-spectraldesc.Rmd'

SUMMARY: processing the following files failed:
  'pavo-2-importing_processing.Rmd' 'pavo-3-analysing.Rmd'

Error: Vignette re-building failed.
Execution halted