Error(s) in re-building vignettes:
--- re-building 'colorSpec-guide.Rmd' using rmarkdown
Error: processing vignette 'colorSpec-guide.Rmd' failed with diagnostics:
DLL 'Rcpp' not found: maybe not installed for this architecture?
--- failed re-building 'colorSpec-guide.Rmd'

--- re-building 'phenolred.Rmd' using rmarkdown
Error: processing vignette 'phenolred.Rmd' failed with diagnostics:
DLL 'Rcpp' not found: maybe not installed for this architecture?
--- failed re-building 'phenolred.Rmd'

--- re-building 'photoncounting.Rmd' using rmarkdown
Error: processing vignette 'photoncounting.Rmd' failed with diagnostics:
DLL 'Rcpp' not found: maybe not installed for this architecture?
--- failed re-building 'photoncounting.Rmd'

--- re-building 'blueflame.rnw' using knitr
This is colorSpec.  Version: 0.8-3.  Author: Glenn Davis [aut, cre].  Built: R 3.6.0; ; 2019-05-27 15:04:05 UTC; windows

Attaching package: 'spacesRGB'

The following objects are masked from 'package:colorSpec':

    RGBfromXYZ, metadata, metadata<-

--- finished re-building 'blueflame.rnw'

--- re-building 'emulation.rnw' using knitr
This is colorSpec.  Version: 0.8-3.  Author: Glenn Davis [aut, cre].  Built: R 3.6.0; ; 2019-05-27 15:04:05 UTC; windows

Attaching package: 'spacesRGB'

The following objects are masked from 'package:colorSpec':

    RGBfromXYZ, metadata, metadata<-

00:39:01.056 WARN  colorSpec::product.colorSpec(). The returned matrix is ambiguous; because it depends on the splitting. Inspect the matrix carefully. 
00:39:01.072 WARN  colorSpec::product.colorSpec(). The returned matrix is ambiguous; because it depends on the splitting. Inspect the matrix carefully. 
--- finished re-building 'emulation.rnw'

--- re-building 'gallery.rnw' using knitr
This is colorSpec.  Version: 0.8-3.  Author: Glenn Davis [aut, cre].  Built: R 3.6.0; ; 2019-05-27 15:04:05 UTC; windows

Attaching package: 'spacesRGB'

The following objects are masked from 'package:colorSpec':

    RGBfromXYZ, metadata, metadata<-

--- finished re-building 'gallery.rnw'

--- re-building 'inversion.rnw' using knitr
This is colorSpec.  Version: 0.8-3.  Author: Glenn Davis [aut, cre].  Built: R 3.6.0; ; 2019-05-27 15:04:05 UTC; windows
--- finished re-building 'inversion.rnw'

--- re-building 'lens-aging.rnw' using knitr
This is colorSpec.  Version: 0.8-3.  Author: Glenn Davis [aut, cre].  Built: R 3.6.0; ; 2019-05-27 15:04:05 UTC; windows

Attaching package: 'spacesRGB'

The following objects are masked from 'package:colorSpec':

    RGBfromXYZ, metadata, metadata<-

--- finished re-building 'lens-aging.rnw'

--- re-building 'optimals.rnw' using knitr
This is colorSpec.  Version: 0.8-3.  Author: Glenn Davis [aut, cre].  Built: R 3.6.0; ; 2019-05-27 15:04:05 UTC; windows
--- finished re-building 'optimals.rnw'

SUMMARY: processing the following files failed:
  'colorSpec-guide.Rmd' 'phenolred.Rmd' 'photoncounting.Rmd'

Error: Vignette re-building failed.
Execution halted