Error(s) in re-building vignettes:
  ...
--- re-building 'GeoLight2.0.Rmd' using rmarkdown
Loading required package: maps
Quitting from lines 108-114 (GeoLight2.0.Rmd) 
Error: processing vignette 'GeoLight2.0.Rmd' failed with diagnostics:
attempt to use zero-length variable name
--- failed re-building 'GeoLight2.0.Rmd'

SUMMARY: processing the following file failed:
  'GeoLight2.0.Rmd'

Error: Vignette re-building failed.
Execution halted
Error(s) in re-building vignettes:
  ...
--- re-building ‘GeoLight2.0.Rmd’ using rmarkdown
Loading required package: maps
Quitting from lines 108-114 (GeoLight2.0.Rmd) 
Error: processing vignette ‘GeoLight2.0.Rmd’ failed with diagnostics:
attempt to use zero-length variable name
--- failed re-building ‘GeoLight2.0.Rmd’

SUMMARY: processing the following file failed:
  ‘GeoLight2.0.Rmd’

Error: Vignette re-building failed.
Execution halted
Error(s) in re-building vignettes:
--- re-building ‘GeoLight2.0.Rmd’ using rmarkdown
Loading required package: maps
Quitting from lines 108-114 (GeoLight2.0.Rmd) 
Error: processing vignette 'GeoLight2.0.Rmd' failed with diagnostics:
attempt to use zero-length variable name
--- failed re-building ‘GeoLight2.0.Rmd’

SUMMARY: processing the following file failed:
  ‘GeoLight2.0.Rmd’

Error: Vignette re-building failed.
Execution halted
Error(s) in re-building vignettes:
--- re-building ‘GeoLight2.0.Rmd’ using rmarkdown
Loading required package: maps
Quitting from lines 108-114 (GeoLight2.0.Rmd) 
Error: processing vignette 'GeoLight2.0.Rmd' failed with diagnostics:
attempt to use zero-length variable name
--- failed re-building ‘GeoLight2.0.Rmd’

SUMMARY: processing the following file failed:
  ‘GeoLight2.0.Rmd’

Error: Vignette re-building failed.
Execution halted
Error(s) in re-building vignettes:
--- re-building 'GeoLight2.0.Rmd' using rmarkdown
Loading required package: maps
Quitting from lines 108-114 (GeoLight2.0.Rmd) 
Error: processing vignette 'GeoLight2.0.Rmd' failed with diagnostics:
attempt to use zero-length variable name
--- failed re-building 'GeoLight2.0.Rmd'

SUMMARY: processing the following file failed:
  'GeoLight2.0.Rmd'

Error: Vignette re-building failed.
Execution halted
Error(s) in re-building vignettes:
--- re-building 'GeoLight2.0.Rmd' using rmarkdown
Loading required package: maps
Quitting from lines 108-114 (GeoLight2.0.Rmd) 
Error: processing vignette 'GeoLight2.0.Rmd' failed with diagnostics:
attempt to use zero-length variable name
--- failed re-building 'GeoLight2.0.Rmd'

SUMMARY: processing the following file failed:
  'GeoLight2.0.Rmd'

Error: Vignette re-building failed.
Execution halted