Error(s) in re-building vignettes:
--- re-building ‘RcppCNPy-intro.Rmd’ using rmarkdown
tlmgr search --file --global '/lettrine.sty'
TeX Live 2018 is frozen forever and will no
longer be updated.  This happens in preparation for a new release.

If you're interested in helping to pretest the new release (when
pretests are available), please read https://tug.org/texlive/pretest.html.
Otherwise, just wait, and the new release will be ready in due time.
Trying to automatically install missing LaTeX packages...
tlmgr install lettrine
TeX Live 2018 is frozen forever and will no
longer be updated.  This happens in preparation for a new release.

If you're interested in helping to pretest the new release (when
pretests are available), please read https://tug.org/texlive/pretest.html.
Otherwise, just wait, and the new release will be ready in due time.
tlmgr: package repository http://mirror.ox.ac.uk/sites/ctan.org/systems/texlive/tlnet (verified)
tlmgr install: package already present: lettrine
tlmgr path add
add_link_dir_dir: /usr/local/share/info/dir exists; not making symlink.
tlmgr search --file --global '/lettrine.sty'
TeX Live 2018 is frozen forever and will no
longer be updated.  This happens in preparation for a new release.

If you're interested in helping to pretest the new release (when
pretests are available), please read https://tug.org/texlive/pretest.html.
Otherwise, just wait, and the new release will be ready in due time.
! LaTeX Error: File `lettrine.sty' not found.

! Emergency stop.
<read *> 

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

--- re-building ‘UsingReticulate.Rmd’ using rmarkdown
tlmgr search --file --global '/lettrine.sty'
TeX Live 2018 is frozen forever and will no
longer be updated.  This happens in preparation for a new release.

If you're interested in helping to pretest the new release (when
pretests are available), please read https://tug.org/texlive/pretest.html.
Otherwise, just wait, and the new release will be ready in due time.
Trying to automatically install missing LaTeX packages...
tlmgr install lettrine
TeX Live 2018 is frozen forever and will no
longer be updated.  This happens in preparation for a new release.

If you're interested in helping to pretest the new release (when
pretests are available), please read https://tug.org/texlive/pretest.html.
Otherwise, just wait, and the new release will be ready in due time.
tlmgr: package repository http://mirror.ox.ac.uk/sites/ctan.org/systems/texlive/tlnet (verified)
tlmgr install: package already present: lettrine
tlmgr path add
add_link_dir_dir: /usr/local/share/info/dir exists; not making symlink.
tlmgr search --file --global '/lettrine.sty'
TeX Live 2018 is frozen forever and will no
longer be updated.  This happens in preparation for a new release.

If you're interested in helping to pretest the new release (when
pretests are available), please read https://tug.org/texlive/pretest.html.
Otherwise, just wait, and the new release will be ready in due time.
! LaTeX Error: File `lettrine.sty' not found.

! Emergency stop.
<read *> 

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

SUMMARY: processing the following files failed:
  ‘RcppCNPy-intro.Rmd’ ‘UsingReticulate.Rmd’

Error: Vignette re-building failed.
Execution halted