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 = 28742 bytes
Input file size = 28856 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 21306
  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 = 21306

Output IDAT size = 21306 bytes (7436 bytes decrease)
Output file size = 21384 bytes (7472 bytes = 25.89% 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 = 28367 bytes
Input file size = 28481 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 20655
  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 = 20655

Output IDAT size = 20655 bytes (7712 bytes decrease)
Output file size = 20733 bytes (7748 bytes = 27.20% 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 = 21505 bytes
Input file size = 21607 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 16120
  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 = 16120

Output IDAT size = 16120 bytes (5385 bytes decrease)
Output file size = 16198 bytes (5409 bytes = 25.03% 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