Error in re-building vignettes:
  ...
trying URL 'http://cran.rstudio.com/bin/windows/contrib/3.5/colorspace_1.4-1.zip'
Content type 'application/zip' length 2549008 bytes (2.4 MB)
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downloaded 2.4 MB

trying URL 'http://cran.rstudio.com/bin/windows/contrib/3.5/farver_2.0.1.zip'
Content type 'application/zip' length 1899491 bytes (1.8 MB)
============================================
downloaded 1.6 MB

trying URL 'http://cran.rstudio.com/bin/windows/contrib/3.5/labeling_0.3.zip'
Content type 'application/zip' length 61756 bytes (60 KB)
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downloaded 60 KB

trying URL 'http://cran.rstudio.com/bin/windows/contrib/3.5/munsell_0.5.0.zip'
Content type 'application/zip' length 244056 bytes (238 KB)
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downloaded 238 KB

trying URL 'http://cran.rstudio.com/bin/windows/contrib/3.5/RColorBrewer_1.1-2.zip'
Content type 'application/zip' length 55498 bytes (54 KB)
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downloaded 54 KB

trying URL 'http://cran.rstudio.com/bin/windows/contrib/3.5/reshape2_1.4.3.zip'
Content type 'application/zip' length 627283 bytes (612 KB)
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downloaded 612 KB

trying URL 'http://cran.rstudio.com/bin/windows/contrib/3.5/scales_1.1.0.zip'
Content type 'application/zip' length 550190 bytes (537 KB)
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downloaded 537 KB

trying URL 'http://cran.rstudio.com/bin/windows/contrib/3.5/viridisLite_0.3.0.zip'
Content type 'application/zip' length 60477 bytes (59 KB)
==================================================
downloaded 59 KB

trying URL 'http://cran.rstudio.com/bin/windows/contrib/3.5/ggplot2_3.2.1.zip'
Content type 'application/zip' length 3958990 bytes (3.8 MB)
==================================================
downloaded 3.8 MB

Quitting from lines 15-19 (single-images.Rmd) 
Error: processing vignette 'single-images.Rmd' failed with diagnostics:
cannot open the connection
Execution halted