Package check result: ERROR

Check: re-building of vignette outputs, Result: ERROR
  Error(s) in re-building vignettes:
    ...
  --- re-building ‘examples.Rmd’ using rmarkdown
  
  Quitting from examples.Rmd:22-30 [setup]
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  <error/rlang_error>
  Error in `library()`:
  ! there is no package called 'igraph'
  ---
  Backtrace:
      ▆
   1. └─base::library(igraph)
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  
  Error: processing vignette 'examples.Rmd' failed with diagnostics:
  there is no package called 'igraph'
  --- failed re-building ‘examples.Rmd’
  
  SUMMARY: processing the following file failed:
    ‘examples.Rmd’
  
  Error: Vignette re-building failed.
  Execution halted