Error(s) in re-building vignettes:
  ...
--- re-building ‘user-guide.Rmd’ using rmarkdown
** Processing: /home/hornik/tmp/R.check/r-devel-gcc/Work/PKGS/spqdep.Rcheck/vign_test/spqdep/vignettes/user-guide_files/figure-html/unnamed-chunk-5-1.png
288x288 pixels, 3x8 bits/pixel, RGB
Input IDAT size = 29408 bytes
Input file size = 29522 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 21786
  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
  zc = 9  zm = 8  zs = 1  f = 5
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 21786

Output IDAT size = 21786 bytes (7622 bytes decrease)
Output file size = 21864 bytes (7658 bytes = 25.94% decrease)

** Processing: /home/hornik/tmp/R.check/r-devel-gcc/Work/PKGS/spqdep.Rcheck/vign_test/spqdep/vignettes/user-guide_files/figure-html/plot mh-1.png
288x288 pixels, 3x8 bits/pixel, RGB
Input IDAT size = 29819 bytes
Input file size = 29933 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 27237
  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
  zc = 9  zm = 8  zs = 1  f = 5
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 27237

Output IDAT size = 27237 bytes (2582 bytes decrease)
Output file size = 27315 bytes (2618 bytes = 8.75% decrease)

** Processing: /home/hornik/tmp/R.check/r-devel-gcc/Work/PKGS/spqdep.Rcheck/vign_test/spqdep/vignettes/user-guide_files/figure-html/plot mh prune-1.png
288x288 pixels, 3x8 bits/pixel, RGB
Input IDAT size = 28643 bytes
Input file size = 28757 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 25872
  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
  zc = 9  zm = 8  zs = 1  f = 5
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 25872

Output IDAT size = 25872 bytes (2771 bytes decrease)
Output file size = 25950 bytes (2807 bytes = 9.76% decrease)

** Processing: /home/hornik/tmp/R.check/r-devel-gcc/Work/PKGS/spqdep.Rcheck/vign_test/spqdep/vignettes/user-guide_files/figure-html/unnamed-chunk-10-1.png
288x288 pixels, 3x8 bits/pixel, RGB
Input IDAT size = 28050 bytes
Input file size = 28164 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 20490
  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
  zc = 9  zm = 8  zs = 1  f = 5
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 20490

Output IDAT size = 20490 bytes (7560 bytes decrease)
Output file size = 20568 bytes (7596 bytes = 26.97% decrease)

** Processing: /home/hornik/tmp/R.check/r-devel-gcc/Work/PKGS/spqdep.Rcheck/vign_test/spqdep/vignettes/user-guide_files/figure-html/unnamed-chunk-10-2.png
288x288 pixels, 3x8 bits/pixel, RGB
Input IDAT size = 21573 bytes
Input file size = 21675 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 16149
  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
  zc = 9  zm = 8  zs = 1  f = 5
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 16149

Output IDAT size = 16149 bytes (5424 bytes decrease)
Output file size = 16227 bytes (5448 bytes = 25.13% decrease)


Quitting from lines 273-279 [unnamed-chunk-11] (user-guide.Rmd)
Error: processing vignette 'user-guide.Rmd' failed with diagnostics:
no applicable method for 'units' applied to an object of class "NULL"
--- failed re-building ‘user-guide.Rmd’

SUMMARY: processing the following file failed:
  ‘user-guide.Rmd’

Error: Vignette re-building failed.
Execution halted