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
--- 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
--- finished re-building ‘cifreg.Rmd’

--- re-building ‘cooking-survival-data.Rmd’ using rmarkdown
--- finished re-building ‘cooking-survival-data.Rmd’

--- re-building ‘glm-utility.Rmd’ using rmarkdown
--- 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
--- finished re-building ‘interval-discrete-survival.Rmd’

--- re-building ‘marginal-cox.Rmd’ using rmarkdown
--- 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
--- finished re-building ‘quantitative-twin.Rmd’

--- re-building ‘recurrent-events.Rmd’ using rmarkdown
--- finished re-building ‘recurrent-events.Rmd’

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

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

--- re-building ‘time-to-event-family-studies-arev.Rmd’ using rmarkdown
--- 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