Error(s) in re-building vignettes:
  ...
--- re-building 'zoningObjects.Rmd' using rmarkdown
Loading required package: spam
Loading required package: dotCall64
Loading required package: grid
Spam version 2.4-0 (2019-11-01) is loaded.
Type 'help( Spam)' or 'demo( spam)' for a short introduction 
and overview of this package.
Help for individual functions is also obtained by adding the
suffix '.spam' to the function name, e.g. 'help( chol.spam)'.

Attaching package: 'spam'

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

    backsolve, forwardsolve

Loading required package: maps
See https://github.com/NCAR/Fields for
 an extensive vignette, other supplements and source code 
New output format of RFsimulate: S4 object of class 'RFsp';
for a bare, but faster array format use 'RFoptions(spConform=FALSE)'.

     PLEASE NOTE:  The components "delsgs" and "summary" of the
 object returned by deldir() are now DATA FRAMES rather than
 matrices (as they were prior to release 0.0-18).
 See help("deldir").
 
     PLEASE NOTE: The process that deldir() uses for determining
 duplicated points has changed from that used in version
 0.0-9 of this package (and previously). See help("deldir").


! Missing number, treated as zero.
<to be read again> 
                   \protect 
l.139 ...nter}\rule{0.5\linewidth}{\linethickness}
                                                  \end{center} 

Error: processing vignette 'zoningObjects.Rmd' failed with diagnostics:
Failed to compile zoningObjects.tex. See https://yihui.name/tinytex/r/#debugging for debugging tips. See zoningObjects.log for more info.
--- failed re-building 'zoningObjects.Rmd'

--- re-building 'zoningSimu.Rmd' using rmarkdown
Loading required package: spam
Loading required package: dotCall64
Loading required package: grid
Spam version 2.4-0 (2019-11-01) is loaded.
Type 'help( Spam)' or 'demo( spam)' for a short introduction 
and overview of this package.
Help for individual functions is also obtained by adding the
suffix '.spam' to the function name, e.g. 'help( chol.spam)'.

Attaching package: 'spam'

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

    backsolve, forwardsolve

Loading required package: maps
See https://github.com/NCAR/Fields for
 an extensive vignette, other supplements and source code 
New output format of RFsimulate: S4 object of class 'RFsp';
for a bare, but faster array format use 'RFoptions(spConform=FALSE)'.

     PLEASE NOTE:  The components "delsgs" and "summary" of the
 object returned by deldir() are now DATA FRAMES rather than
 matrices (as they were prior to release 0.0-18).
 See help("deldir").
 
     PLEASE NOTE: The process that deldir() uses for determining
 duplicated points has changed from that used in version
 0.0-9 of this package (and previously). See help("deldir").


! Missing number, treated as zero.
<to be read again> 
                   \protect 
l.139 ...nter}\rule{0.5\linewidth}{\linethickness}
                                                  \end{center} 

Error: processing vignette 'zoningSimu.Rmd' failed with diagnostics:
Failed to compile zoningSimu.tex. See https://yihui.name/tinytex/r/#debugging for debugging tips. See zoningSimu.log for more info.
--- failed re-building 'zoningSimu.Rmd'

SUMMARY: processing the following files failed:
  'zoningObjects.Rmd' 'zoningSimu.Rmd'

Error: Vignette re-building failed.
Execution halted