Error(s) in re-building vignettes:
--- re-building ‘basic-dutils.Rmd’ using rmarkdown

Quitting from basic-dutils.Rmd:190-193 [unnamed-chunk-15]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<error/rlang_error>
Error in `structure()`:
! attempt to set an attribute on NULL
---
Backtrace:
    ▆
 1. └─mets::dstr(melanoma)
 2.   └─mets::daggregate(...)
 3.     └─base::structure(res, ngroupvar = 0, class = c("daggregate", class(res)))
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Error: processing vignette 'basic-dutils.Rmd' failed with diagnostics:
attempt to set an attribute on NULL
--- failed re-building ‘basic-dutils.Rmd’

--- re-building ‘binomial-family.Rmd’ using rmarkdown
--- finished re-building ‘binomial-family.Rmd’

--- re-building ‘binomial-twin.Rmd’ using rmarkdown
--- finished re-building ‘binomial-twin.Rmd’

--- re-building ‘binreg-TRS.Rmd’ using rmarkdown
Using optipng is skipped as output is variable
--- finished re-building ‘binreg-TRS.Rmd’

--- re-building ‘binreg-ate.Rmd’ using rmarkdown
--- finished re-building ‘binreg-ate.Rmd’

--- re-building ‘binreg.Rmd’ using rmarkdown
--- finished re-building ‘binreg.Rmd’

--- re-building ‘cifreg.Rmd’ using rmarkdown
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
--- finished re-building ‘cifreg.Rmd’

--- re-building ‘cooking-survival-data.Rmd’ using rmarkdown
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
--- finished re-building ‘cooking-survival-data.Rmd’

--- re-building ‘glm-utility.Rmd’ using rmarkdown
Using optipng is skipped as output is variable
--- finished re-building ‘glm-utility.Rmd’

--- re-building ‘haplo-discrete-ttp.Rmd’ using rmarkdown
--- finished re-building ‘haplo-discrete-ttp.Rmd’

--- re-building ‘interval-discrete-survival.Rmd’ using rmarkdown
Using optipng is skipped as output is variable
--- finished re-building ‘interval-discrete-survival.Rmd’

--- re-building ‘marginal-cox.Rmd’ using rmarkdown
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
--- finished re-building ‘marginal-cox.Rmd’

--- re-building ‘mediation-survival.Rmd’ using rmarkdown
--- finished re-building ‘mediation-survival.Rmd’

--- re-building ‘phreg_rct.Rmd’ using rmarkdown
--- finished re-building ‘phreg_rct.Rmd’

--- re-building ‘quantitative-twin.Rmd’ using rmarkdown
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
--- finished re-building ‘quantitative-twin.Rmd’

--- re-building ‘recurrent-events.Rmd’ using rmarkdown
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
--- finished re-building ‘recurrent-events.Rmd’

--- re-building ‘rmst-ate.Rmd’ using rmarkdown
Using optipng is skipped as output is variable
--- finished re-building ‘rmst-ate.Rmd’

--- re-building ‘survival-ate.Rmd’ using rmarkdown
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
--- finished re-building ‘survival-ate.Rmd’

--- re-building ‘time-to-event-family-studies-arev.Rmd’ using rmarkdown
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
Using optipng is skipped as output is variable
--- finished re-building ‘time-to-event-family-studies-arev.Rmd’

--- re-building ‘twostage-survival.Rmd’ using rmarkdown
--- finished re-building ‘twostage-survival.Rmd’

--- re-building ‘while-alive.Rmd’ using rmarkdown
--- finished re-building ‘while-alive.Rmd’

SUMMARY: processing the following file failed:
  ‘basic-dutils.Rmd’

Error: Vignette re-building failed.
Execution halted