Error(s) in re-building vignettes:
  ...
--- re-building ‘model.Rmd’ using rmarkdown
--- finished re-building ‘model.Rmd’

--- re-building ‘performance.Rmd’ using rmarkdown
** Processing: /home/hornik/tmp/R.check/r-devel-clang/Work/PKGS/melt.Rcheck/vign_test/melt/vignettes/performance_files/figure-html/unnamed-chunk-4-1.png
2100x1500 pixels, 8 bits/pixel, 255 colors in palette
Reducing image to 8 bits/pixel, grayscale
Input IDAT size = 48584 bytes
Input file size = 49499 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 37133
  zc = 9  zm = 8  zs = 1  f = 0
  zc = 1  zm = 8  zs = 2  f = 0
  zc = 9  zm = 8  zs = 3  f = 0
  zc = 9  zm = 8  zs = 0  f = 5		IDAT size = 30564
  zc = 9  zm = 8  zs = 1  f = 5		IDAT size = 29997
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 1  f = 5		IDAT size = 29997

Output IDAT size = 29997 bytes (18587 bytes decrease)
Output file size = 30075 bytes (19424 bytes = 39.24% decrease)

** Processing: /home/hornik/tmp/R.check/r-devel-clang/Work/PKGS/melt.Rcheck/vign_test/melt/vignettes/performance_files/figure-html/unnamed-chunk-6-1.png
2100x1500 pixels, 8 bits/pixel, 255 colors in palette
Reducing image to 8 bits/pixel, grayscale
Input IDAT size = 46620 bytes
Input file size = 47535 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 34303
  zc = 9  zm = 8  zs = 1  f = 0
  zc = 1  zm = 8  zs = 2  f = 0
  zc = 9  zm = 8  zs = 3  f = 0
  zc = 9  zm = 8  zs = 0  f = 5		IDAT size = 27263
  zc = 9  zm = 8  zs = 1  f = 5		IDAT size = 26817
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 1  f = 5		IDAT size = 26817

Output IDAT size = 26817 bytes (19803 bytes decrease)
Output file size = 26895 bytes (20640 bytes = 43.42% decrease)

--- finished re-building ‘performance.Rmd’

--- re-building ‘article.Rnw’ using knitr
Error: processing vignette 'article.Rnw' failed with diagnostics:
Running 'texi2dvi' on 'article.tex' failed.
LaTeX errors:
! Undefined control sequence.
l.914 \hlkwd{library}\hldef
                           {(}\hlsng{"melt"}\hldef{)}
? 
! Emergency stop.
! Emergency stop.
l.914 
      
End of file on the terminal!

!  ==> Fatal error occurred, no output PDF file produced!
--- failed re-building ‘article.Rnw’

SUMMARY: processing the following file failed:
  ‘article.Rnw’

Error: Vignette re-building failed.
Execution halted